PROPRIETARY CPM Rex 121 Tool steels

Material group: Ferrous Alloys / Tool steels

Country / Standard: PROPRIETARY

Data updates

Latest Update: 2025-09

Total number of updates: 3

Update History

2015-08 2014-04

This material has 30 properties — only a subset is shown here.

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PROPRIETARY CPM Rex 121 Chemical Composition

CRITERIA

VALUE

UNIT

CAS NUMBER

CRITERIA

VALUE

≤ 3.4000

UNIT

CAS NUMBER

7440-44-0

CRITERIA

VALUE

≤ 9.0000

UNIT

CAS NUMBER

7440-48-4

CRITERIA

VALUE

≤ 4.0000

UNIT

CAS NUMBER

7440-47-3

CRITERIA

VALUE

val1

UNIT

CAS NUMBER

7439-98-7

CRITERIA

VALUE

val1

UNIT

CAS NUMBER

7440-62-2

CRITERIA

VALUE

val1

UNIT

CAS NUMBER

7440-33-7

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PROPRIETARY CPM Rex 121 Physical Properties

Temperature

0 - 30°C 100 - 300°C ≥ 300°C

PROPERTY / VALUE

Modulus of Elasticity

190 — 214 GPa

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Density

7.72 — 8.25 kg/dm³

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Poisson Coefficient

0.27 — 0.3

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This material has 30 properties — only a subset is shown here.

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PROPRIETARY CPM Rex 121 Heat Treatments

ANNEALING it is heated slowly and uniform to a temperature of 900 °C, maintains the temperature for 2 hours and allows to cooling to 590 °C in the furnace at a cooling rate no faster than 10 °C. It is then further cooled in still air down to room temperature. The typical annealed hardness achieved by a soft annealing is approximately HB360/410. STRESS RELIEVING Stress relieving follows rough machining by heating to 600 - 700 °C. Once complete heat penetration has been reached, the material is allowed to cool in the furnace to approx. 500 °C followed by cooling in air. HARDENING usually involves the use of 2 - 3 preheating stages (450 – 500 °C / 850 – 900 °C / 1010-1065°C). Immediately following this it is heated to the required austenitizing temperature of 1025 – 1220 °C. QUENCHING Air, hot bath or interrupted oil quenching can be used. In case of vacuum heat treatment, due regard is to be given to applying an appropriate quenching rate (at least at 5 bar pressure). For attaining ideal toughness properties it is recommended to apply the bath quenching method. TEMPERING Immediately temper after the material has cooled down below 40°C. Triple tempering with a holding time of 2 hours is each stage at the tempering temperature is necessary. Normally, it is tempered with a temperature range of 550 – 595 °C. SURFACE TREATMENTS it can be nitrided or PVD/ CVD coated.

PROPRIETARY CPM Rex 121 Mechanical Properties

Temperature

0 - 30°C

PROPERTY / VALUE

Brinell Hardness (HB)

360 — 410

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Rockwell Hardness (HR)

38 — 44

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-Cross References

12Composition
2Mechanical Properties
10Physical Properties
1Heat Treatment
1Metallography
-Machinability

-Stress-Strain
-Formability
-Fatigue
-Fracture
-Creep

-Joints
-Coatings
-Dimensions
-Tribology

-Corrosion
-Ageing
-Weatherability
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