CHAMPALOY
(AISI L6)
Champaloy is a tough, high-strength oil-hardening tool steel suitable for general purpose applications.
Typical Chemistry
Carbon 0.75%
Manganese 0.70%
Silicon 0.25%
Chromium 0.80%
Nickel 1.50%
Molybdenum 0.30%
Typical Applications
Form Rolls Straightening Rolls
Brake Dies Shear Blades
Machine Tool Parts Collets
Chucks Pinions
Hardening
Note: Full hardness will only be attained in sections less than about 3 inches thick.

Critical Temperature: 1325F(720C)

Preheat: 1250/1350F(675/730C)

High Heat: 1500/1550F(815/845C), hold 10/30 minutes at temperature. Quench: Quench in oil to hand warm, 150F(65C). For minimum distortion, parts may be removed from oil at about 400F(205 C), and air-cooled to hand warm.

Temper: 350/600F(175/315C); hold one hour per inch of thickness, two hours minimum, four hours preferred.

Cryogenic treatments: Refrigeration treatments may improve long-term dimensional stability by transforming retained austenite. Refrigeration treatments should be performed after at least one temper, to minimize risk of cracking, and should always be followed by a temper.
Typical Properties
Hardness and Impact Toughness Data
Oil quenched from 1500F(815C)
Tempering
Temperature
Hardness
Toughness,
Charpy C-notch
°F
°C
HRC
ft-lbs
Joules
As quenched 63-65 - -
300 150 63-65 15 20
400 205 60-62 43 58
500 260 58-60 38 52
600 315 56-58 68 92
700 370 53-55 - -
Size Change During Hardening
Oil quenched from 1525F(830C)
Tempered
Length Change
°F
°C
%
300 150 + 0.11%
400 205 + 0.10%
500 260 + 0.14%
Surface Treatments
Champaloy can be given standard surface treatments such as hard chrome plating if desired. Nitriding is not generally practical due to a substantial loss of core hardness.

Annealing
A. Heat to 1375/1425F(745/775C), hold two hours, cool slowly, 50F(30C) per hour maximum, to below 1100F(540C), then air cool.
OR
B. Heat to 1375/1425F(745/775C), hold two hours, cool to 1200/1250F(650/675C) hold 4 to 6 hours, then air cool.
Typical annealed hardness: 187/235 BHN

Stress Relieving

Annealed Material: 1100/1300F(595/740C), hold 2 hours, cool in still air.

Hardened Material: 50F(30C) below last tempering temperature, hold two hour, cool in still air.

Welding
Use oil-hardening (L6, O1) tool steel filler material.

Annealed material: Preheat to 400/600F(205/315C). Maintain over 400F(205C) during welding. Allow to cool to hand warm (150F(65C) after welding. Reanneal, or temper 1250/1300F(675/705C) for 6 hours.

Hardened material: Preheat to 50F(30C) below tempering temperature (300F(150C) minimum). Maintain over 300F(150C) during welding. Allow to cool to hand warm (150F(65C)) after welding. Retemper at 25/50F(15/30C) below original tempering temperature.

Physical Properties
Modulus of Elasticity ...................................................................30 psi x 106 (207 GPa)
Density .......................................................................................0.284 lb/in3 (7860 kg/m3)
Specific gravity ..............................................................................................................7.86
Thermal Conductivity .................. 200F(95C) ............... 20 BTU/hr/ft/°F (34.5 W/m°K)
Thermal Expansion
Temperature
Range
Coefficient of Thermal
Expansion
°F
°C
in/in/°Fx10-6
mm/mm/°Cx10-6
RT-200
RT-95
6.3
11.3
RT-400
RT-205
7.0
12.6
RT-800
RT-425
7.0
12.6
RT-1000
RT-540
7.5
13.5
RT-1200
RT-650
7.6
13.7
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