EDELSTAHL WITTEN-KREFELD GMBH - SERVICES … · Special engineering steels EDELSTAHL WITTEN-KREFELD GMBH Nitriding steels NITRODUR NITRODUR NITRODUR NITRODUR NITRODUR NITRODUR

Special engineering steels

EDELSTAHL WITTEN-KREFELD GMBH

Nitriding steels

NITRODURNITRODUR

NITRODUR

NITRODURNITRODUR

NITRODUR

2

3

Contents

Page 4 – 5 General

Page 6 – 7 Special features

Page 8 – 9 Steel portraits

Page 10 – 11 Application examples

Page 12 – 13 Steel production

Page 14 – 15 Steel processing

Page 16 Overview of grades and

chemical composition

Page 17 Forms supplied

Page 18 – 29 Material data sheets

Page 30 Sampling according to DIN EN 10085

Page 31 – 35 Nitriding and nitrocarburising

of steel components

Page 36 Temperature comparison

Page 37 Hardness comparison table

Page 38 List of photos

The use of special, high-perfor-

mance steel grades is essential

whenever machines and compo-

nents are exposed to high surface

stresses and dynamic loads.

If high surface hardness and

fatigue strength are required in

applications also involving high

temperatures, a product such as

our Nitrodur steel is the material

of choice.

Nitrodur is the name of our nitrid-

ing steel grades optimised for

use at elevated temperatures.

Different surface hardnesses and

hardening profiles can be set by

varying the nitriding parameters.

The advantage compared to the

surface hardening of standard

heat-treatable steel grades is the

lower distortion, as there are no

transformation processes during

cooling from the nitriding temper-

ature.

Our Nitrodur steel grades acquire

their high yield point, tensile and

fatigue strength (combined with

high toughness!) as a result of

hardening with tempering at

above 550 °C, but below the

microstructural transformation

temperature. The great strength

of our Nitrodur steel grades is

their optimum adaptation to the

respective intended application.

Depending on the cross-section

of the workpiece, optimum

quenching and tempering is en-

sured by selecting the appropri-

ate steel grade. The unusual

degree of purity and the homo-

geneity of the microstructure

guarantee uniform mechanical

properties, even where large

dimensions are involved.

Edelstahl Witten-Krefeld is in a

position to supply round billets of

up to approx. 750 mm diameter.

In this context, the strength and

toughness can be specifically

adjusted and combined to meet

the demands on the respective

component. Nitrodur steels offer

excellent hot formability. Their

cold formability and machinability

are dependent on the analysis

and the crystalline structure.

Nitrodur –

4

NITRODUR

Appropriate alloying and heat

treatment permit adjustment of

the material for optimum machin-

ability.

The top quality of Nitrodur is

achieved through high process

reliability and modern installations

for melting, secondary metallurgy,

vertical continuous casting, re-

melting, hot forming and heat

treatment, as well as through

advanced test facilities.

Edelstahl Witten-Krefeld is in a

position to offer you a tailor-made

nitriding steel for every applica-

tion and every component. Ask

our material specialists for ad-

vice.

Nitrodur – a speciality

from Edelstahl Witten-Krefeld

the right one for hot jobs

5

General

6

Spot-on analysis

The strength and toughness of

the base material are determined

by its chemical composition and

the heat treatment it undergoes.

Consequently, the required prop-

erties are already specifically

aimed for when melting the steel.

The facilities in Witten and

Krefeld enable us to achieve a

spot-on, reliably reproducible

chemical composition.

Specific hardenability

The hardenability of the material

can be specifically adapted to the

geometry of the respective com-

ponent by selecting the right

alloying elements. The most

important alloying elements for

nitriding steels are chromium,

nickel, aluminium, molybdenum

and vanadium. We offer not only

aluminium-alloyed nitriding steels,

but also aluminium-free grades.

Maximum purity

Extremely high purity is achieved

by secondary metallurgical treat-

ment and vertical continuous

casting, or also by remelting.

Undesirable non-metallic inclu-

sions are reduced to a minimum.

The homogeneity of our Nitrodur

steels cannot be beaten by any

other manufacturer of high-grade

steel.

High fatigue strength

In nitriding steels, the different

service properties required for the

individual components, such as

high strength under static and

dynamic stress, high toughness

and nitriding hardness, are set by

way of the chemical composition

and a sequence of heat treatment

operations. The nitriding treat-

ment increases wear resistance

and fatigue strength.

Nitrodur – specifically

7

Special features

Good machinability

The greater the number of com-

ponents to be manufactured, the

more important it is for the mate-

rial to have good machinability. In

other words: the cost-efficiency

of series production is already

partly determined when ordering

a specific steel grade.

Customised heat treatment

Depending on the envisaged

application and processing, we

can supply you with Nitrodur steel

grades in a wide variety of treated

conditions, e.g. with a defined

strength range.

Detailed technical information on

as-delivered conditions and pro-

cessing can be found starting on

Page 16.

adaptedto elevated temperatures

Nitrodur – steel grades

that get straight to the point

8

We’ve got the finest

Rolled or forged

Edelstahl Witten-Krefeld supplies

a wide variety of rolled and forged

products in different heat-treated

conditions, from bar steel, uni-

versal plate/flat dimensions and

semis, all the way to open-die

forgings.

Our partners in the steel trade

offer a wide selection of Nitrodur

grades in all standard sizes.

Unmachined or machined

Our strength is steel grades not

only in a variety of hot-formed

products, but also at various pro-

cessing stages. Our processing

operations range from rough-

machining and bright surfaces with

close tolerances, all the way to

ready-to-install components. Make

use of our extensive capabilities

and let us act as your “extended

workbench”.

Talk to our specialists about the

individual, tailor-made Nitrodur

solution you need.

NITRODUR

NITRODUR 14 CrMoV 5-9

NITRODUR 31 CrMo 12

NITRODUR 31 CrMoV 9

NITRODUR 34 CrAlNi 7

NITRODUR 41 CrAlMo 7

9

Steel portraits

specialitiesin stock for you

• NITRODUR 15 CrMoV 5-9Al-free nitriding steel with good high-temper-

ature strength, high fatigue strength and tem-

pering resistance, as well as optimum full

quenching and tempering.

Can be used as a nitriding, case-hardening or

heat-treatable steel. Particularly suitable for

quenched and tempered extrusion dies.

Suitable for welding by any method.

• NITRODUR 31 CrMo 12Al-free nitriding steel for relatively large

cross-sections, and also for higher nitriding

hardnesses as a result of its chemical com-

position. Suitable for gear wheels, cylinders,

drills, connecting rods, shafts, extruders,

guides, straightening rolls, thread gauges

with relatively large cross-sections.

• NITRODUR 31 CrMoV 9Al-free nitriding steel grade for relatively low

nitriding hardnesses and relatively great

nitriding depths. Suitable for gear wheels,

cylinders, drills, connecting rods, shafts,

extruders, guides, straightening rolls, thread

gauges.

• NITRODUR 34 CrAlNi 7Al-alloyed nitriding steel grade for large

cross-sections. Suitable for piston rods,

extruders, cylinders, gear wheels, rings.

• NITRODUR 41 CrAlMo 7Al-alloyed nitriding steel for medium cross-

sections. Suitable for connecting rods, small

extruders, valve stems.

• NITRODUR 34 CrAlMo 5Al-alloyed nitriding steel for high nitriding

hardnesses and small heat-treatment cross-

sections. Suitable for valve stems, super-

heated-steam fittings, cam plates, small gear

wheels, eccentrics.

34 CrAlMo 5 Talk to our

specialists for hot subjects

10

Nitrodur – hardness

Plastics processing

Cylinders and barrels, rams,

screws, injection nozzles and

other components are exposed to

great stress during injection

moulding, compression moulding

and extrusion. Consistently high

hardness must be retained, even

at elevated working temperatures,

in order to guarantee consistent

precision of the products to be

manufactured. Nitrodur offers just

that.

Gearbox construction

When made of Nitrodur, pinions,

toothed wheels and gear wheels

with external and internal gearing

offer greater operating reliability

and a longer service life in power

stations. Nitrodur steel grades are

also the perfect material if, after

heat treatment, the components

cannot be re-worked as a result of

their geometry or their small size.

Engine construction

For engines, such as racing-car

engines, which are exposed to

extreme stresses, particularly in

relation to temperature, it is advis-

able to use special Nitrodur steel

grades to manufacture crank-

shafts, connecting rods, piston

pins, cylinders, cylinder liners and

drive chains.

General mechanical engineering

Nitrodur steels grades are recom-

mended in mechanical engineer-

ing wherever reliable operation

and precision functioning at ele-

vated temperatures are indis-

pensable. For instance, in the pro-

duction of pump drive shafts, tim-

ing chains, pistons for hydraulic

controllers, screws and worm

gears, spindles, straightening rolls,

superheated-steam fittings, value

guides and valve seats.

11

Application examples

and precisionfor increased safety

Tool-making

When it comes to precision

mechanical parts and tools that

work at elevated operating tem-

peratures, Nitrodur guarantees the

unchanging geometry of the com-

ponents, such as sizing rolls, ring

gauges, thread gauges, limit plug

gauges, gear wheels and piston

rods. Nitrodur steel grades are

also particularly suitable materials

in cases where very small compo-

nents cannot be mechanically re-

worked after being heat-treated.

Machine tool manufacture

Nitrodur steel grades ensure a

long service life, reliable operation

and consistently high precision in

machine tools. For example, in

spindles and guide rails, grinding

and drilling machines, as well as

milling machines and lathes.

12

Our expertise in steel is Our own steel production in our

modern steelworks in Witten is

the basis for the purity and homo-

geneity of our heat-treatable

steels. Precisely defined proper-

ties are achieved by means of

exact alloying and process speci-

fications for melting, forming

and heat treatment. The steels

are melted in a 130 t electric arc

furnace.

The metallurgical precision work

is performed in a downstream

ladle furnace of the same size.

Depending on the steel grade and

the dimensions of the end prod-

uct, the steel melted in this way is

cast in ingots or continuous cast

blooms. Over 50 different mould

formats are available for ingot

casting, ranging from 600 kg to

160 t.

The continuous cast blooms are

manufactured in two strands on a

vertical continuous casting ma-

chine in a 475 x 340 mm format.

A remelting steelworks with two

electroslag remelting (ESR) fur-

naces and two vacuum arc re-

reactions, such as desulphurisa-

tion, and acting as an anti-oxidant

for the melting bath of the new

ingot. In addition, the slag has a

high capacity for absorbing non-

metallic inclusions, which means

that the remelted material is free

of coarse inclusions. The im-

provement in the microscopic

melting (VAR) furnaces is avail-

able in Krefeld for the production

of heat treatable steels involving

particularly stringent demands in

terms of homogeneity of their

microstructure and their purity.

Electroslag remelting

process

In the electroslag remelting

process (ESR), which works with

alternating current, a cast or

forged, self-consuming electrode

is immersed in a bath of molten

slag, which serves as an electrical

resistor.

The material to be remelted drips

from the end of the electrode

through the slag and forms the

new ingot in a water-cooled

mould below. The heat dissipa-

tion leads to directional solidifica-

tion in the direction of the longi-

tudinal ingot axis.

The remelting slag fulfils several

functions in this process. On the

one hand, it develops the neces-

sary process heat, while at the

same time supporting chemical

Scrap 130-t-electricarc furnace

Ladle degas-sing station(VD/VOD)

ca

Remelting facilities

ESR

VAR

I

EDELSTAHL WITTEN-KREFELD GMBH

THYSSEN KRUPP STAHL AG

Main production routes

Ladlefurnace

13

production something you can rely on

purity is attributable to desulphur-

isation and the resultant high

degree of sulphidic purity, and

also to a reduction in the size and

quantity of oxidic inclusions.

Nitrodur – reliable materials

thanks to reliable processes

Steel production

NITRODUR

Continuous bloomaster, 475 x 340 mm,

2 strands

Blooming/billet/large-sizebar rolling mill

Untreated

As-rolled

LSX 25

33 MN pressLSX 55

Long forging machines

As-forged

Finishingdepartments,rolling mills

Finishingdepartments,forging shops

Heattreatmentfacilities

Blooming-slabbing mill

Ingot casting

Machining

Products

Peelingmachines

• As-cast ingots As-continuously cast bloom material

• Open-die forgingsas-forged or machined

• Forged semis

• Forged round billets for tubemakingas-forged or peeled

• Forged bar steelas-forged or machined

• Machined tool steelforged or rolled

• Rolled semis

• Rolled tube roundsas-rolled or peeled

• Rolled bar steelas-rolled or machined

• Universal plate and flats

• Special products

Nitrodur –just

Vacuum arc remelting

process

The vacuum arc remelting (VAR)

process works with cast or

forged, self-consuming elec-

trodes in a vacuum.

Using an electric arc in a vacuum,

a melting bath is generated in a

copper crucible, which acts as

the opposite pole to the remelting

electrode and is connected to a

DC voltage source via current

contacts.

A new ingot is formed from the

liquefied electrode material drop

by drop in a continuous process.

In the VAR process, refinement of

the steel is brought about by the

reaction of the oxygen dissolved

in the steel with the carbon in the

molten material under the effect

of the vacuum. This results in the

best possible degree of micro-

scopic oxidic purity and freedom

from macroscopic inclusions. As

no desulphurisation takes place

during this remelting process, the

lowest possible sulphur content

has to be set prior to remelting, in

order also to meet the most strin-

gent demands on the degree of

sulphidic purity. Moreover, this

process guarantees the lowest

possible quantities of dissolved

gases in the steel and a homo-

geneous microstructure free of

segregation.

Hot forming and finishing

The blooming mill in Witten pro-

duces semi-finished products,

steel bars and universal plate/flat

dimensions. Two modern finishing

lines for checking the inner and

outer surface condition, as well

as the dimensions and identity,

are available for rolled and forged

products and steel bars. The

forge is equipped with a 33 MN

press, a GFM LSX 55 horizontal

long forging machine and a GFM

LSX 25 long forging machine.

14

Steel processing

nitriding steel, the way you need it

Machining

Edelstahl Witten-Krefeld offers

not only an optimum material in

various forms, but also pre-

machined and ready-to-install

parts. We put extensive consult-

ing know-how and modern ma-

Krefeld and Witten. Rotationally

symmetrical parts with a piece

weight of up to 20 tonnes are

manufactured in Krefeld on con-

ventional and modern CNC lathes

and grinding machines. The key

production fields are shafts, cylin-

ders and rolls for continuous

casting.

chining facilities at the disposal

of our customers.

After straightening, rolled or

forged bar steel and round billets

up to 300 mm diameter for tube-

making can be peeled, pressure

polished and chamfered in

15

1.8521

1.8515

1.8519

1.8550

1.8509

1.8507

0.13 –0.18

0.28 –0.35

0.27 –0.34

0.30 –0.37

0.38 –0.45

0.30 –0.37

1.20 –1.50

2.80 –3.30

2.30 –2.70

1.50 –1.80

1.50 –1.80

1.00 –1.30

0.80 –1.10

0.30 –0.50

0.15 –0.25

0.15 –0.25

0.20 –0.35

0.15 –0.25

0.20 –0.30

–

0.10 –0.20

–

–

–

–

–

–

0.85 –1.15

–

–

0.80 –1.10

0.40 –0.70

0.40 –0.70

0.40 –0.70

0.40 –0.70

0.40 –0.70

–

–

–

0.80 –1.20

0.80 –1.20

0.80 –1.20

≤ 0.40

≤ 0.40

≤ 0.40

≤ 0.40

≤ 0.40

≤ 0.40

≤ 0.025

≤ 0.025

≤ 0.025

≤ 0.025

≤ 0.025

≤ 0.025

≤ 0.030

≤ 0.035

≤ 0.035

≤ 0.035

≤ 0.035

≤ 0.035

16

Overview of gradesand chemical composition

Overview of grades Table 1

Chemical composition Table 2

Steel grade Chemical composition to DIN EN 10085, except1 (% by weight)

Code DIN EN Mate-name 10085 rial No. C Si Mn P max. S Al Cr Mo Ni V

Nitrodur 15 CrMoV 5-91

Nitrodur 31 CrMo12

Nitrodur 31 CrMoV 9

Nitrodur 34 CrAlNi 7

Nitrodur 41 CrAlMo 7

Nitrodur 34 CrAlMo 5

15CrMoV5-9

31CrMo12

31CrMoV9

34CrAlNi7

41CrAlMo7

34CrAlMo5

Grades Material No. Code name acc. Standardised into EN 10085

Page 18 – 19 Nitrodur 15 CrMoV 5-9 1.8521 15CrMoV5-9 DIN 17211

Page 20 – 21 Nitrodur 31 CrMo12 1.8515 31CrMo12 EN 10085

Page 22 – 23 Nitrodur 31 CrMoV 9 1.8519 31CrMoV9 EN 10085

Page 24 – 25 Nitrodur 34 CrAlNi 7 1.8550 34CrAlNi7 EN 10085

Page 26 – 27 Nitrodur 41 CrAlMo 7 1.8509 41CrAlMo7 EN 10085

Page 28 – 29 Nitrodur 34 CrAlMo 5 1.8507 34CrAlMo5 EN 10085

1) DIN 17211

17

NITRODUR

Forms supplied

55 – 250 mm dia.

Sharp-edged50 – 160 mm square

DIN 1014

DIN 7527

DIN 1013

> 200 mm dia. standard in-company tolerance, closertolerance on request

Subject topurchaseorder

Special:*)≤ +100/-0

Flat:Width: 80 – 510 mmThickness: 25 – 160 mmWidth/thickness ratio 10:1 max

Width: 25 – 160 mm

Thickness:80 – 550 mm

65 – 750 mm dia.

265 – 650 mm square

flat: on request

50 – 320 mm square,rising in 1 mm incre-ments

52 – 400 mm dia.

52 – 300 mm dia.

DIN 1017up to 150 mm width and 60 mm thickness;over 150 mm widthstandard in-company toler-ance

Tolerance on request

≤ 210 mm +/- 2%> 210 mm +/- 3%of edge length

Special:*)≤ 100 mm +/- 1%

of edge length

> 100 mm – 210 mm

+/- 1.5% of edge length

ISA Tol. 11 or comparabletolerance

ISA Tol. 11 or comparabletolerance

ISA-Tol. 8 or comparable tolerance

≤ 80 mm: 4.0 mm/m

> 80 mm: 2.5 mm/m

4.0 – 10 m,other lengthson request

Lengths as a function ofdimensionsand heat-treatmentcondition on request

3 - 10 m, onrequest 30 mmax. as afunction ofdia. andmax. bardead weightof 7 t

Hot-sawn or hot abra-sive-cut

Special:*)Cold-sawn,cold abrasive-cut

Hot abrasive-cut or cold-sawn

Special:*)Cold abrasive-cut

≤ 210 mm square:hot-sawn or hot abra-sive-cut

> 210 mm square:hot-sheared

Special:*)Cold abrasive-cut, cold-sawn

Hot-sawn/hotabrasive-cut

Special:*)Cold-sawn/abrasive-cut

Dimensions 50- 105 mm withround chamfer30° or 45°,chamfer widthapprox. 5 -12mm, otherwidths by ar-rangement

Rough-peeled finishavailable for 52 -240 mm

Max. permissiblesurface defectdepths:

Round: 1% max. ofdia. + 0.05 mm

Square: 1% max. ofedge length

Flat: 1.5% max. ofwidth, 2.0% max. ofthickness

Special:*)Smaller surfacedefect depth onrequest

Special:*)

- Rough-peeled- Turned- Milled

Edge radius:

≤ 210 mm - 12-18%of edge length

> 210 mm: withoutdefined edge radius

Max. perm. surfacedefect depth:

≤ 140 mm sq.0.3 mm max.

> 140 - 200 mm sq.0.6 mm max.

> 200 mm sq.visible defects elimi-nated

Technically crack-freecondition e.g. eddy-current tested orcomparable tech-nique, defined depthof roughness andsuitable packaging byspecial arrangement

< 1000 mm2:4.0 mm/m

> 1000 mm2:2.5 mm/m

Special:*)Speciallystraightened

Standard: 6 mm/m

Special:*)4 mm/m

As-peeledstraightness ≤ 2 mm/m, 1 mm/m orcloser as afunction ofdimensions on request

Untreated

Cold-shear-able

Cold-sawable

Normalized

Treated toferrite-pearlitestructure

Treated tohardnessrange

Soft-annealed

Spheroidize-annealed

Stress-relieved

Quenchedand tempered

Bar steeland roundbillets fortubemakingrolled

Sheet barsrolled withbulbous nar-row face

Bar steeland semis forged

Semisrolled

Bright steel

peeled

peeled andpolished

*) Special finishes subject to further inquiry (partly dependent on quality, dimensions and condition)

ground 52 – 100 mm dia.

Semis:as-forgedstraightness

Bar steel:to DIN withinthe tolerancelimit

3 – 8 m

Surface finishAs-suppliedcondition

End condition

Lengths/weightsStraightnessLengthsDia. or edge length

TolerancesProduct Dimensions

on requestAs-castingots/c.c.blooms Open-dieforgings

Forgings forged toshape on request(drawing)

18

C

0.13 – 0.18

Si

≤0.40

Mn

0.80 – 1.10

P

≤0.025

S

≤0.030

Cr

1.20 – 1.50

Mo

0.80 – 1.10

V

0.20 – 0.30

NITRODUR® 15 CrMoV 5-9

Material No.

1.8521

Code

15CrMoV5-9

Typical analysis in %acc. to DIN 17211

To DIN 17211

To DIN 17211

Material No.Code

Chemicalcomposition

Mechanical properties in differenttreatment conditions

Heat treatmentdiameter

in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2

Tensile strengthin N/mm2

Rm

Elongation atfracture in %

Amin.

Reduction ofarea at fracture

in % Zmin.

Notch impact energy(ISO-V)in J Av

min.

≤ 100

100 < d ≤ 250

750

700

900 – 1100

850 – 1050

10

12

–

–

30

35

Quenched and tempered QT

Hardness in differenttreatment conditions

Treated forshearing S

HB

max. 255

Soft annealedA

HB

max. 248

Nitrided,surface hardness

HV1

approx. 800

Soft annealing

680 – 740

Hardening

940 – 980

Quenching medium

Oil/polymer or water

Tempering

600 – 700

Nitriding

500 – 580

Heat treatment

To DIN 17211Temperatures in °C

From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion

Coefficient of linear thermalexpansion α 10-6 K-1

Temperature in °C

ApplicationsAl-free nitriding steel with good high-temperature strength, high fatigue strength and tempering resistance, as wellas optimum full quenching and tempering. Can be used as a nitriding, case-hardening or heat-treatable steel.Particularly suitable for quenched and tempered extrusion dies. Suitable for welding by any method.

19

NITRODUR® 15 CrMoV 5-9

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10 427

353

337 337 336 325 322 269292

236

278

Ac3

Ac1

A

MS

M

F

10

90

205 50 60 75

B

363 353393

250

500

750

1000

1250

1500

1750

2000

500 550 600 650 700 7500

800

200

175

150

0

125

100

75

50

25

100,0

87,5

75,0

62,5

50,0

37,5

25,0

12,5

0,0450

Rm

Rp0,2

Z

A5

Av

Tempering diagram High-temperature strength diagram

Time-temperature-transformation diagram(continuous)

1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

200

175

150

125

100

75

Rm

Rp0,2

Z

A5

ISO-V

DVM

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at f

ract

ure

Z in

%

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Pre-treatment: 980 °C, 30 min./airHardening: 980 °C, 30 min./oilHeat treatment cross-section: 60 mm dia.

Tempering temperature in °C (tempering time: 2 hours)

Test temperature in °C

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in min

Time in h

20

NITRODUR® 31 CrMo 12

acc. to DIN EN 10085Typical analysis in %

To DIN EN 10085

To DIN EN 10085

Material No.Code

Chemicalcomposition




HB

max. 255

Soft annealedA

HB

max. 248


HV1

approx. 800

Soft annealing

650 – 700

Hardening

870 – 930

Quenching medium


Tempering

580 – 700

Nitriding

480 – 570

Heat treatment

To DIN EN 10085Temperatures in °C

From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion


Temperature in °C

ApplicationsAl-free nitriding steel for relatively large cross-sections, and also for higher nitriding hardnesses as a result of itschemical composition. Suitable for gear wheels, cylinders, drills, connecting rods, shafts, extruders, guides,straightening rolls, thread gauges with relatively large cross-sections.

C

0.28 – 0.35

Si

≤0.40

Mn

0.40 – 0.70

P

≤0.025

S

≤0.035

Cr

2.80 – 3.30

Mo

0.30 – 0.50

Material No.

1.8515

Code

31CrMo12


in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2


Rm


Amin.


in % Zmin.


min.

16 ≤ d ≤ 240

40 < d ≤ 100

100 < d ≤ 160

160 < d ≤ 250

835

785

735

675

1030 – 1230

1980 – 1180

930 – 1130

880 – 1080

10

11

12

12

–

–

–

–

25

30

30

30


21

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10

548530 525 498 493 421 397 394

327337

330 238

Ac3

Ac1

A

MS

M

P

105

9515

11

5

92

3

40

3

8235

B

97 98 94 62

3

200

600

400

800

1000

1200

1400

1600

1800

2000

100 200 300 400 500 6000

700

200

180

160

140

120

0

100

80

60

40

20

100

90

80

70

60

50

40

30

20

10

0

Rm

Rp0,2

Z

Av

A5


1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

200

175

150

125

100

75

Rm

Rp0,2

Z

A5

ISO-V

DVM

NITRODUR® 31 CrMo 12Tempering diagram High-temperature strength diagram



0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at fr

actu

re Z

in %


Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in h

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

Time in min

22

NITRODUR® 31 CrMoV 9


Material No.Code

Chemicalcomposition




HB

max. 255

Soft annealedA

HB

max. 248


HV1

approx. 800

Soft annealing

680 – 720

Hardening

870 – 930

Quenching medium


Tempering

580 – 700

Nitriding

480 – 570

Heat treatment


From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion


Temperature in °C

ApplicationsAl-free nitriding steel grade for relatively low nitriding hardnesses and relatively great nitriding depths. Suitable forgear wheels, cylinders, drills, connecting rods, shafts, extruders, guides, straightening rolls, thread gauges.

C

0.27 – 0.34

Si

≤0.40

Mn

0.40 – 0.70

P

≤0.025

S

≤0.035

Cr

2.30 – 2.70

Mo

0.15 – 0.25

V

0.10 – 0.20

Material No.

1.8519

Code

31CrMoV9


in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2


Rm


Amin.


in % Zmin.


min.

16 ≤ d ≤ 240

40 < d ≤ 100

100 < d ≤ 160

160 < d ≤ 250

900

800

700

650

1100 – 1300

1000 – 1200

1900 – 1100

1850 – 1050

19

10

11

12

–

–

–

–

25

30

35

40


To DIN EN 10085

To DIN EN 10085

23

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10 478496 481 493 428 404 390 351374351 264 186

Ac3

Ac1

A

MS

M

F

1005060

340 30

B

97

70

177 170

172

100 100 100100

60

P

70 70

30 30

7030

200

600

400

800

1000

1200

1400

1600

1800

2000

100 200 300 400 500 6000

700

200

180

160

140

120

0

100

80

60

40

20

100

90

80

70

60

50

40

30

20

10

0

Rm

Rp0,2

Z

Av

A5


1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

200

175

150

125

100

75

Rm

Rp0,2

Z

A5

ISO-V

DVM

NITRODUR® 31 CrMoV 9Tempering diagram High-temperature strength diagram



0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at f

ract

ure

Z in

%


Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in min

Time in h

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

24

NITRODUR® 34 CrAINi 7


Material No.Code

Chemicalcomposition




HB

max. 255

Soft annealedA

HB

max. 248


HV1

approx. 950

Soft annealing

650 – 700

Hardening

870 – 930

Quenching medium


Tempering

580 – 700

Nitriding

480 – 570

Heat treatment


From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion


Temperature in °C

ApplicationsAl-alloyed nitriding steel grade for large cross-sections. Suitable for piston rods, extruders, cylinders, gear wheels,rings.

C

0.30 – 0.37

Si

≤0.40

Mn

0.40 – 0.70

P

≤0.025

S

≤0.035

AI

0.80 – 1.20

Cr

1.50 – 1.80

Mo

0.15 – 0.25

Ni

0.85 – 1.15

Material No.

1.8550

Code

34CrAINi7


in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2


Rm


Amin.


in % Zmin.


min.

16 ≤ d ≤ 240

40 < d ≤ 100

100 < d ≤ 160

160 < d ≤ 250

680

650

600

600

1900 – 1100

1850 – 1050

1800 – 1000

1800 – 1000

10

12

13

13

–

–

–

–

30

30

35

35


To DIN EN 10085

To DIN EN 10085

25

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10 534

566

543 505 368383

442

333 293

Ac3

Ac1A

MS

F

305

2

3 1540

B

95

233

219

348

1580

9060

P

50

361 240

9080

4050 50

50 50 50

200

600

400

800

1000

1200

1400

1600

1800

2000

100 200 300 400 500 6000

700

200

180

160

140

120

0

100

80

60

40

20

100

90

80

70

60

50

40

30

20

10

0

Rm

Rp0,2

Z

Av

A5


1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

200

175

150

125

100

75

Rm

Rp0,2

Z

A5

ISO-V

DVM

NITRODUR® 34 CrAINi 7Tempering diagram High-temperature strength diagram



0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at f

ract

ure

Z in

%


Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in min

Time in h

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

26

NITRODUR® 41 CrAIMo 7


Material No.Code

Chemicalcomposition




HB

max. 255

Soft annealedA

HB

max. 248


HV1

approx. 950

Soft annealing

650 – 700

Hardening

870 – 930

Quenching medium


Tempering

580 – 700

Nitriding

480 – 570

Heat treatment


From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion


Temperature in °C

ApplicationsAl-alloyed nitriding steel for medium cross-sections. Suitable for connecting rods, small extruders, valve stems.

C

0.38 – 0.45

Si

≤0.40

Mn

0.40 – 0.70

P

≤0.025

S

≤0.035

AI

0.80 – 1.20

Cr

1.50 – 1.80

Mo

0.20 – 0.35

Material No.

1.8509

Code

41CrAIMo7


in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2


Rm


Amin.


in % Zmin.


min.

16 ≤ d ≤ 240

40 < d ≤ 100

100 < d ≤ 160

160 < d ≤ 250

750

720

670

625

1950 – 1150

1900 – 1100

1850 – 1050

1800 – 1000

11

13

14

15

–

–

–

–

25

25

30

30


To DIN EN 10085

To DIN EN 10085

27

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10 613 599 595 409483

590

339 244

Ac3

Ac1

A

MS

F

103

3 15

B

95

223 206375

55

8540

P25

92

3030

75 70

M

70

30

~

~

~~

200

600

400

800

1000

1200

1400

1600

1800

2000

100 200 300 400 500 6000

700

200

180

160

140

120

0

100

80

60

40

20

100

90

80

70

60

50

40

30

20

10

0

Rm

Rp0,2

Z

A5

Av


1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

175

150

125

100

75

50

50

Rm

Rp0,2

Z

A5

ISO-V

DVM

NITRODUR® 41 CrAIMo 7Tempering diagram High-temperature strength diagram



0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at f

ract

ure

Z in

%


Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in min

Time in h

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

28

NITRODUR® 34 CrAIMo 5


Material No.Code

Chemicalcomposition




HB

max. 255

Soft annealedA

HB

max. 248


HV1

approx. 950

Soft annealing

650 – 700

Hardening

870 – 930

Quenching medium


Tempering

580 – 700

Nitriding

480 – 570

Heat treatment


From -191to +16

9.1

20100

11.1

20200

12.1

20300

12.9

20400

13.5

20500

13.9

Thermal expansion


Temperature in °C

ApplicationsAl-alloyed nitriding steel for high nitriding hardnesses and small heat-treatment cross-sections. Suitable for valvestems, superheated-steam fittings, cam plates, small gear wheels, eccentrics.

C

0.30 – 0.37

Si

≤0.40

Mn

0.40 – 0.70

P

≤0.025

S

≤0.035

AI

0.80 – 1.20

Cr

1.00 – 1.30

Mo

0.15 – 0.25

Material No.

1.8507

Code

34CrAIMo5


in mmØ

0.2% proofstress

(Rp 0.2) min.N/mm2


Rm


Amin.


in % Zmin.


min.

16 ≤ d ≤ 240

40 < d ≤ 100

600

600

1800 – 1000

1800 – 1000

14

14

–

–

35

35


To DIN EN 10085

To DIN EN 10085

29

200

600

400

800

1000

1200

1400

1600

1800

2000

100 200 300 400 500 6000

700

200

180

160

140

120

0

100

80

60

40

20

100

90

80

70

60

50

40

30

20

10

0

Rm

Rp0,2

Z

Av

A5

1200

100 200 300 400 500 600 700RT

1000

800

600

400

200

90

80

70

60

30

20

10

200

175

150

125

100

75

Rm

Rp0,2

Z

A5

ISO-V

DVM

NITRODUR® 34 CrAIMo 5Tempering diagram High-temperature strength diagram

1200

1100

1000

900

800

700

600

500

400

300

200

100

0

100 101 102

100 101 102 103 104

100 101 102 103 104 105 106

HV 10

472

490 460 383 345

318

293

287 265

260 229 192

Ac3

Ac1

A

MS

M

F

7

10

5

30

15 50

179

174

1744560

6575 80

80

B

1010 50

45 5050

50 P50

50




0.2%

pro

of s

tres

s R

p0.

2an

d t

ensi

le s

tren

gth

Rm

in N

/mm

2

Not

ch im

pac

t en

ergy

Av

in J

(IS

O-V

)

Elo

ngat

ion

at f

ract

ure

A5

and

red

uctio

n o

f ar

ea

at f

ract

ure

Z in

%


Tem

per

atur

e in

°C

Hardnessvalues

Time in s

Time in min

Time in h

No

tch

imp

act

ener

gy

E

long

atio

n

R

educ

tion

of

0

.2%

pro

of

stre

ss R

p0.

2an

d

Av

in J

at

fra

ctur

e

are

a at

fra

ctur

e

te

nsile

str

eng

th R

m in

N/m

m2

A5

in %

Z in

%

30

Samplingaccording to DIN EN 10085

Sampling of bar steel and wire rod

d up to 25 mm 1) d over 25 mm a up to 25 mm 1)

b ≥ aa over 25 mmb ≥ a

Round sections Square and rectangular sections

Tensile specimen notched bar impact specimen

For thin products (d or b ≤ 25 mm) the specimen should,as far as possible, consist of an unmachined part of the bar.

With products having a round section, the longitudinal axle of the notchshould be generally in the direction of a diameter.

With products having rectangular sections, the longitudinal axle of the notchmust be at right angles to the wider roll surface.

d

d

d

12.5

d

12.5

12.5

a

b

12.5

a

b

12.5

a

b

12.5

12,5

b

a

12.5

2) 3) 3)

1)

2)

3)

The values given for the mechani-

cal properties in the material data

sheets apply to samples in the

“quenched and tempered” heat-

treated condition, taken in accor-

dance with DIN EN 10085.

31

Technical information

The surfaces of steel components

are subject to a wide variety of

stresses, such as wear, rolling and

bending stresses. In such cases,

it makes sense to increase the re-

sistance to such stresses on the

surface of the component by way

of appropriate hardening.

Nitriding and nitrocarburising are

two hardening processes with

particularly low distortion. In con-

trast to flame, induction and case

hardening, where the increase in

hardness is achieved by micro-

structural transformation of the

steel, low treatment temperatures

are sufficient for nitriding and ni-

trocarburising.

Temperatures of 490 to 530 °C are

customary for nitriding, while ni-

trocarburising is performed at

temperatures of 550 to 580 °C.

The two processes differ in that

nitrogen alone is used for nitrid-

ing, whereas nitrocarburising in-

volves a simultaneous combina-

tion of nitrogen and carbon.

Nitriding and nitrocarburisingof steel components

The aim of nitriding is to form a

diffusion layer (precipitation layer)

with a material-dependent nitrid-

ing depth of up to 0.9 mm. The

prerequisite for successful nitrid-

ing is the use of alloyed steel

grades containing nitride-forming

elements (Al, Cr, V, Mo, Mn). Only

in this way is it possible for so-

called alloy nitrides to form, which

in turn create high residual com-

pression stresses in the case.

The achievable surface hardness

is dependent not only on the ni-

triding temperature and the

amount of nitrogen available, but

particularly also on the quantity of

nitride-forming elements and the

strength of the components in

quenched and tempered condi-

tion. The higher the content of

these elements, the higher the

surface hardness after nitriding.

Aluminium is a particularly effec-

tive element when it comes to in-

creasing hardness by nitriding.

For instance, surface hardnesses

of approx. 1000 HV can be

achieved in a steel grade contain-

ing 1% aluminium. In steel grades

that contain no aluminium, but

roughly 1% chromium, the achiev-

able surface hardness is in the re-

gion of 600 HV. In order to obtain

a surface hardness of approx.

1000 HV in chrome steels, the

chromium content has to be in-

creased to approx. 5%. The differ-

ent effects of the alloying ele-

ments is clearly illustrated by

hardness profiles, such as shown

in Figs. 1 and 2 (Page 32) for com-

parable nitriding parameters.

The top diagram applies to a

31 CrMoV 9 steel and the bottom

diagram to a 34 CrAlNi 7 steel.

The carbon content of the steels

to be nitrided should not exceed

0.5%, as most nitride-forming ele-

ments also form carbides and sta-

ble carbides only allow limited

binding of nitrogen.

32

Gas-nitrided

500°C 10 to 20h

500°C 36h

500°C 84h

Hardness profiles of NITRODUR 31 CrMoV 9 steel after different nitriding times Fig. 1

Surface hardness to DIN EN 10085

1200

1000

800

600

400

200

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8

Distance from the surface in mm

HV

0,5

Hardness profiles of NITRODUR 34 CrAlNi 7 steel after different nitriding times Fig. 2


1200

1000

800

600

400

200

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8


HV

0,5

Gas-nitrided

500°C 10 to 20h

500°C 36h

500°C 84h





33


Consequently, nitriding results in

increasingly high surface hard-

nesses at increasing strengths in

Q+T condition, as the carbides

present are less stable.

Nitriding treatment can be carried

out in gas or plasma. Ammonia

gas (NH3) is used as the nitrogen

source in gas nitriding.

It dissociates at the surface of the

steel, which acts as a catalyst.

The nitrogen, which is then pres-

ent in atomic form, diffuses into

the steel surface and combines

with the iron there to form iron ni-

tride (Fe2-3 N, Fe4 N). The nitrogen

diffuses further into the material in

the course of treatment, leading

to the formation of the alloy ni-

trides.

In plasma nitriding, the compo-

nents to be treated are loaded

into a vacuum retort that is fed

with a mixture of nitrogen and hy-

drogen as the treatment gas. A

plasma is ignited by applying a

constant or pulsating direct volt-

age (300 to 800 V) between the

components, which act as the

cathode, and the retort, which

serves as the anode. The ionised

nitrogen molecules hit the surface

of the components with high ki-

netic energy, are split into nitrogen

atoms and trigger the nitriding

process, which then takes place

via the diffusion processes de-

scribed. As atoms are also de-

tached from the surface at the

same time, this process also per-

mits the nitriding of corrosion-re-

sistant steel grades by way of de-

struction of the passive chromium

oxide layer.

The aim of nitrocarburising is to

form a largely monophase ε-com-

pound layer (Fe2-3 N), which is sta-

bilised by the addition of carbon

to the treatment cycle. This layer

possesses high hardness, as well

as good sliding, wear and anti-

corrosion properties. Its thickness

is usually approx. 10 to 20 µm.

The precipitation layer below it

has a material-dependent depth

of approx. 0.2 to 0.4 mm. This

method is particularly suitable for

plain steels, which cannot be ni-

trided owing to the absence of ni-

tride-forming elements. Nitrocar-

burising can be performed in a

salt bath (Tenifer treatment), in

gas or in plasma. This process

should not be used when aiming

for relatively great depths of nitra-

tion, as high nitrogen concentra-

tions are required and lengthy

treatment times would otherwise

involve a risk of embrittlement of

the nitrided layer.

34

Hardness testing

Nitrided layers should be tested

using the hardness test according

to Vickers. A test load of 5 daN

has proven successful (HV 5).

Higher test loads falsify the re-

sults, as the hardness of the core

has a major influence on the test

results.

When testing nitrocarburised lay-

ers, a test load of 1 daN (HV 1)

has become generally accepted

for material testing. The exact

hardness of the compound layer

can only be measured by micro-

hardness testing.

The depth of nitration is deter-

mined on the cross-section by

low-load hardness testing with

the HV 0.5 test load in accor-

dance with DIN 50190, Part 3.

Fatigue strength

Nitriding generates residual com-

pression stresses in the case, re-

sulting in increased fatigue

strength. Precise information as to

the degree of improvement, e.g. in

the fatigue test under reversed

bending stresses, cannot be

given, as the result is influenced

by a host of factors. By way of ap-

proximation, it can be assumed

that the fatigue strength in ni-

trided condition is approx. 30%

higher than in quenched and tem-

pered condition.

As a special safety precaution

during nitriding and during the

subsequent loading of nitrided

workpieces in operation, it should

be pointed out that there must be

no defects in the brittle nitrided

layer, which can be damaged by

even slight impact loads. Surface

defects lead to a notch effect,

which eliminates the advantages

of the nitriding process and has a

negative effect on the service life

of the workpiece. Bearing this in

mind, it is advisable to use ni-

trided surfaces primarily in cases

of severe wear, but on surfaces

which should not be exposed to

any impact-type stresses, if at all

possible.

Corrosion resistance of

nitrided components

The corrosion resistance of the

iron nitride layer is greater than

that of the nitrided steel in its

original condition. However, in or-

der to exploit this effect to the full,

this layer must be free of pores,

as discontinuities in the formation

Advantages of the methods de-

scribed:

• Wear-resistant surfaces

• High fatigue strength

• Good sliding properties

• High temperature resistance

• Low distortion

• Good corrosion resistance

(nitrocarburising)

The methods have the following

disadvantages:

• Relatively low hardening

depth

• Occasionally long treatment

times

• Sensitivity to shock loads

35


C ≤ 0.45 ± 0.02

Si ≤ 0.40 + 0.03

Mn ≤ 0.80 ± 0.04

P ≤ 0.025 + 0.005

S ≤ 0.035 + 0.005

Al ≥ 0.80 ≤ 1.20 ± 0.10

Cr ≥ 1.00 ≤ 2.00 ± 0.05> 2.00 ≤ 3.50 ± 0.10

Mo ≤ 0.30 ± 0.03> 0.30 ≤ 1.00 ± 0.04

Ni ≤ 1.15 ± 0.05

Sn ≤ 0.030 + 0.005

V ≤ 0.25 + 0.021 ± means that, for a given melt, either the upper or the lower limit of the range given for theladle analysis in Table 2 may be exceeded, but not both at once.

Maximum permissiblecontent in the ladle analysis

% by weight

Deviation from limit1 of the check analysis from the defined ladle analysis

to DIN EN 10085

Permissible deviations between check analysis and ladle analysis Table 3

Element

of the nitride layer and in the con-

centration profile again reduce the

degree of additional corrosion re-

sistance. This applies to the nitrid-

ing steels described in this

brochure. However, in the possi-

ble event of nitriding chromium-

containing stainless materials –

with 13 or 17% Cr – the corrosion

resistance must be expected to

decline after nitriding in compari-

son with that of the base material.

Temperature Comparison

Chart

°C °F K °C °F K °C °F K

–273.15 –459.67 0.00 380.00 716.00 653.15 910.00 1670.00 1183.15

–270.00 –454.00 3.15 390.00 743.00 663.15 920.00 1688.00 1193.15

–200.00 –328.00 73.15 400.00 752.00 673.15 930.00 1706.00 1203.15

–150.00 –238.00 123.15 410.00 770.00 683.15 940.00 1724.00 1213.15

–100.00 –148.00 173.15 420.00 788.00 693.15 950.00 1742.00 1223.15

– 90.00 –130.00 183.15 430.00 806.00 703.15 960.00 1760.00 1233.15

– 80.00 –112.00 193.15 440.00 824.00 713.15 970.00 1778.00 1243.15

– 70.00 – 94.00 203.15 450.00 842.00 723.15 980.00 1796.00 1253.15

– 60.00 – 76.00 213.15 460.00 860.00 733.15 990.00 1814.00 1263.15

– 50.00 – 58.00 223.15 470.00 878.00 743.15 1000.00 1832.00 1273.15

– 40.00 – 40.00 233.15 480.00 896.00 753.15 1010.00 1850.00 1283.15

– 30.00 – 22.00 243.15 490.00 914.00 763.15 1020.00 1868.00 1393.15

– 20.00 – 4.00 253.15 500.00 932.00 773.15 1030.00 1886.00 1303.15

– 17.78 0.00 255.37 510.00 950.00 783.15 1040.00 1904.00 1313.15

– 10.00 14.00 263.15 520.00 968.00 793.15 1050.00 1922.00 1323.15

0.00 32.00 273.15 530.00 986.00 803.15 1060.00 1940.00 1333.15

10.00 50.00 283.15 540.00 1004.00 813.15 1070.00 1958.00 1343.15

20.00 68.00 293.15 550.00 1022.00 823.15 1080.00 1976.00 1353.15

30.00 86.00 303.15 560.00 1040.00 833.15 1090.00 1994.00 1363.15

40.00 104.00 313.15 570.00 1058.00 843.15 1100.00 2012.00 1373.15

50.00 122.00 323.15 580.00 1076.00 853.15 1110.00 2030.00 1383.15

60.00 140.00 333.15 590.00 1094.00 863.15 1120.00 2048.00 1393.15

70.00 158.00 343.15 600.00 1112.00 873.15 1130.00 2066.00 1403.15

80.00 176.00 353.15 610.00 1130.00 883.15 1140.00 2084.00 1413.15

90.00 194.00 363.15 620.00 1148.00 893.15 1150.00 2102.00 1423.15

100.00 212.00 373.15 630.00 1166.00 903.15 1160.00 2120.00 1433.15

110.00 230.00 383.15 640.00 1184.00 913.15 1170.00 2138.00 1443.15

120.00 248.00 393.15 650.00 1202.00 923.15 1180.00 2156.00 1453.15

130.00 266.00 403.15 660.00 1220.00 933.15 1190.00 2174.00 1463.15

140.00 284.00 413.15 670.00 1238.00 943.15 1200.00 2192.00 1473.15

150.00 302.00 423.15 680.00 1256.00 953.15 1210.00 2210.00 1483.15

160.00 320.00 433.15 690.00 1274.00 963.15 1220.00 2228.00 1493.15

170.00 338.00 443.15 700.00 1292.00 973.15 1230.00 2246.00 1503.15

180.00 356.00 453.15 710.00 1310.00 983.15 1240.00 2264.00 1513.15

190.00 374.00 463.15 720.00 1328.00 993.15 1250.00 2282.00 1523.15

200.00 392.00 473.15 730.00 1346.00 1003.15 1260.00 2300.00 1533.15

210.00 410.00 483.15 740.00 1364.00 1013.15 1270.00 2318.00 1543.15

220.00 428.00 493.15 750.00 1382.00 1023.15 1280.00 2336.00 1553.15

230.00 446.00 503.15 760.00 1400.00 1033.15 1290.00 2354.00 1563.15

240.00 464.00 513.15 770.00 1418.00 1043.15 1300.00 2372.00 1573.15

250.00 482.00 523.15 780.00 1436.00 1053.15 1310.00 2390.00 1583.15

260.00 500.00 533.15 790.00 1454.00 1063.15 1320.00 2408.00 1593.15

270.00 518.00 543.15 800.00 1472.00 1073.15 1330.00 2426.00 1603.15

280.00 536.00 553.15 810.00 1490.00 1083.15 1340.00 2444.00 1613.15

290.00 554.00 563.15 820.00 1508.00 1093.15 1350.00 2462.00 1623.15

300.00 572.00 573.15 830.00 1526.00 1103.15 1360.00 2480.00 1633.15

310.00 590.00 583.15 840.00 1544.00 1113.15 1370.00 2498.00 1643.15

320.00 608.00 593.15 850.00 1562.00 1123.15 1380.00 2516.00 1653.15

330.00 626.00 603.15 860.00 1580.00 1133.15 1390.00 2234.00 1663.15

340.00 644.00 613.15 870.00 1598.00 1143.15 1400.00 2552.00 1673.15

350.00 662.00 623.15 880.00 1616.00 1153.15 1500.00 2732.00 1783.15

360.00 680.00 633.15 890.00 1634.00 1163.15 2000.00 3632.00 2273.15

370.00 698.00 643.15 900.00 1652.00 1173.15 2500.00 4532.00 2773.15

°C °F K

X = Particular K X– 273 9/5 (X–273) + 32 X

measured °C X 9/5 X + 32 X + 273

temperature °F 5/9 (X–32) X 5/9 (X–32) + 273

36

37


Hardness comparison table

Tensile strength, Brinell, Vickers and Rockwell hardness

Tensilestrength

RmN/mm2

Ball inden-tation mm

d HB

Brinell hardness Vickershardness

HV

Rockwell hardness

HRB HRC HR 30 N

255 6.63 76.0 80 – – –270 6.45 80.7 85 41.0 – –285 6.30 85.5 90 48.0 – –305 6.16 90.2 95 52.0 – –320 6.01 95.0 100 56.2 – –335 5.90 99.8 105 – – –350 5.75 105 110 62.3 – –370 5.65 109 115 – – –385 5.54 114 120 66.7 – –400 5.43 119 125 – – –415 5.33 124 130 71.2 – –430 5.26 128 135 – – –450 5.16 133 140 75.0 – –465 5.08 138 145 – – –480 4.99 143 150 78.7 – –495 4.93 147 155 – – –510 4.85 152 160 81.7 – –530 4.79 156 165 – – –545 4.71 162 170 85.0 – –560 4.66 166 175 – – –575 4.59 171 180 87.1 – –595 4.53 176 185 – – –610 4.47 181 190 89.5 – –625 4.43 185 195 – – –640 4.37 190 200 91.5 – –660 4.32 195 205 92.5 – –675 4.27 199 210 93.5 – –690 4.22 204 215 94.0 – –705 4.18 209 220 95.0 – –720 4.13 214 225 96.0 – –740 4.08 219 230 96.7 – –755 4.05 223 235 – – –770 4.01 228 240 98.1 20.3 41.7785 3.97 233 245 – 21.3 42.5800 3.92 238 250 99.5 22.2 43.4820 3.89 242 255 – 23.1 44.2835 3.86 247 260 (101) 24.0 45.0850 3.82 252 265 – 24.8 45.7865 3.78 257 270 (102) 25.6 46.4880 3.75 261 275 – 26.4 47.2900 3.72 266 280 (104) 27.1 47.8915 3.69 271 285 – 27.8 48.4930 3.66 276 290 (105) 28.5 49.0950 3.63 280 295 – 29.2 49.7965 3.60 285 300 – 29.8 50.2995 3.54 295 310 – 31.0 51.3

1030 3.49 304 320 – 32.2 52.31060 3.43 314 330 – 33.3 53.61095 3.39 323 340 – 34.4 54.41125 3.34 333 350 – 35.5 55.41155 3.29 342 360 – 36.6 56.41190 3.25 352 370 – 37.7 57.41220 3.21 361 380 – 38.8 58.41255 3.17 371 390 – 39.8 59.31290 3.13 380 400 – 40.8 60.21320 3.09 390 410 – 41.8 61.11350 3.06 399 420 – 42.7 61.91385 3.02 409 430 – 43.6 62.71420 2.99 418 440 – 44.5 63.51455 2.95 428 450 – 45.3 64.31485 2.92 437 460 – 46.1 64.91520 2.89 447 470 – 46.9 65.71555 2.86 (456) 480 – 47.7 66.41595 2.83 (466) 490 – 48.4 67.11630 2.81 (475) 500 – 49.1 67.71665 2.78 (485) 510 – 49.8 68.31700 2.75 (494) 520 – 50.5 69.01740 2.73 (504) 530 – 51.1 69.51775 2.70 (513) 540 – 51.7 70.01810 2.68 (523) 550 – 52.3 70.51845 2.66 (532) 560 – 53.0 71.21880 2.63 (542) 570 – 53.6 71.71920 2.60 (551) 580 – 54.1 72.11955 2.59 (561) 590 – 54.7 72.71995 2.57 (570) 600 – 55.2 73.2

Tensilestrength

RmN/mm2

Ballindentation

mm d HB

Brinell hardness Vickershardness

HV

Rockwell hardness

HRB HRC HR 30 N

2030 2.54 (580) 610 – 55.7 73.72070 2.52 (589) 620 – 56.3 74.22105 2.51 (599) 630 – 56.8 74.62145 2.49 (608) 640 – 57.3 75.12180 2.47 (618) 650 – 57.8 75.5

– – – 660 – 58.3 75.9– – – 670 – 58.8 76.4– – – 680 – 59.2 76.8– – – 690 – 59.7 77.2– – – 700 – 60.1 77.6– – – 720 – 61.0 78.4– – – 740 – 61.8 79.1– – – 760 – 62.5 79.7– – – 780 – 63.3 80.4– – – 800 – 64.0 81.1– – – 820 – 64.7 81.7– – – 840 – 65.3 82.2– – – 860 – 65.9 82.7– – – 880 – 66.4 83.1– – – 900 – 67.0 83.6– – – 920 – 67.5 84.0– – – 940 – 68.0 84.4

Tensile strength N/mm2 Rm

Brinell hardness1) Diameter of the d1) Calculated from: ball indentation in mm

HB = 0.95 · HV

(0.102 F/D2 = 30) Hardness HBD = 10 value =

Vickers hardness Diamond pyramid HVTest forces ≥ 50 N

Rockwell hardness Ball 1.588 mm (1/16“) HRBTotal test force = 98 N

Diamond cone HRCTotal test force = 1471 N

Diamond coneTotal test force = 294 N HR 30 N

0.102 · 2 Fπ D (D – √D2 – d2)

Conversions of hardness values using this conversion table are only approximate.See DIN 50 150, December 1976.

38

Page Source Object/Motif

Cover Bernex Müller Screw3 Bernex Müller Screw4 Bernex Xaloy Twin cylinder4 Carl Gommann Gear wheel4 – 5 Carl Gommann Gear wheels5 Steinmetz Team meeting6 Bernex Xaloy Cylinder6 Brüninghaus Hydromatic A4VG variable displacement pump6 – 7 Cincinnati Extrusion Screw6 - 7 Cincinnati Extrusion Screws7 Carl Gommann Gear wheels7 Cincinnati Extrusion Screws

8 Steinmetz Material store for rotary hearth furnace8 - 9 Steinmetz Rudder spindles/shafts9 Company photo Bar stock store10 Bavaria Hydroelectric power station10 Company photo Wheel loader10 Bavaria Formula 1 racing car10 Bernex Xaloy Screw10 Bernex Xaloy Screw10 Brüninghaus Hydromatic Axial piston motor11 Zefa Motorcycle11 Steinmetz Bumper production11 Carl Gommann Gear wheel12 Company photo Electric arc furnace12 Company photo Vacuum plant12 Company photo Continuous casting plant12 Company photo Slab13 Company photo ESR plant14 Company photo Control room, 3000 t press14 Company photo Forging bar steel14 Company photo Blooming mill14-15 Steinmetz Rotary hearth furnace15 Calow Peeling machine15 Steinmetz Removal from the rotary hearth furnace33 Bernex Xaloy Cylinder35 Cincinnati Extrusion Screw35 Cincinnati Extrusion Screw kit36 Carl Gommann Gear wheels

List of photos

39

General note (liability)

All statements regarding the properties

of utilisation of the materials or products

mentioned are for the purposes of

description only. Guarantees regarding

the existence of certain properties or a

certain utilisation are only ever valid if

agreed upon in writing.

EDELSTAHL WITTEN-KREFELD GMBHAuestrasse 4, 58452 Witten/GERMANY · Tel. (+49) (0)2302/294307 · Fax (+49) (9)2302/294308

E-mail: [email protected] · Internet: www.edelstahl-witten-krefeld.de

• Sales - Nitriding steelsTel. (+49) (0)2302/294346 · Fax (+49) (0)2302/294687E-mail: [email protected]

• Quality DepartmentTel. (+49) (0)2302/294020 · Fax (+49) (0)2302/294436Tel. (+49) (0)2151/832046 · Fax (+49) (0)2151/8341563 41 56

c2/2

001

Nitriding steels

NITRODURNITRODUR

NITRODUR

NITRODURNITRODUR

NITRODUR

Documents

EDELSTAHL WITTEN-KREFELD GMBH - SERVICES … · Special engineering steels EDELSTAHL WITTEN-KREFELD GMBH Nitriding steels NITRODUR NITRODUR NITRODUR NITRODUR NITRODUR NITRODUR