Crucible® CPM MagnaCut

Description

For more information visit:
https://knifesteelnerds.com/2021/03/25/cpm-magnacut/

Heat Treatment Recommendations for CPM MagnaCut:

WRAP IN KNU-FOIL PRIOR TO HARDENING, PLATE QUENCH BETWEEN THICK ALUMINIUM / STEEL PLATES.

Recommended Heat Treatment:
Harden at 1120°C for 15 minutes.

Quench to below 50°C.

Double temper at 175°C 2 hrs. minimum each temper.

Cool to hand warm between tempers. A freeze treatment may be added after the quench. Aim hardness: 60-63 HRC.

 

Forging: 1150°C. Do not forge below 950°C.
Annealing: Heat to 900°C, hold 2 hours, slow cool no faster than 15°C per hour to 595°C, then furnace cool or cool in still air to room temperature. Annealed Hardness: About BHN 235

Stress Relieving:
Annealed Parts: Heat to 595-705°C, hold 2 hours, then furnace cool or cool in still air.
Hardened Parts: Heat to 15-30°C below original tempering temperature, hold 2 hours, then furnace cool or cool in still air.
Straightening: Best done warm at 200-425°C.

Hardening:
Preheat: Heat to 845-870°C Equalize.
Austenitize: 1065-1205°C, hold time at temperature as shown in the chart above. Thick cross-sections and larger pieces may need longer austenitizing time.
Quench: Plate quench, air or positive pressure quench (2 bar minimum) to below 50°C, or salt or interrupted oil quench to about 540°C, then air cool to below 50°C.

Cold Treatment: A cold treatment may be used after the quench to decrease retained austenite and increase hardness. Tempering before the cold treatment decreases the effectiveness of the cold treatment but also decreases the chance of warping or cracking.
A freezer treatment at -23°C has no effect unless performed directly after the quench with no delay.
Temper: Double temper at 150-230°C. Hold for 2 hours minimum each time.

NOTE: Tempering above 400°C results in a decrease in corrosion resistance.

Size Change: +0.05 to +0.10% when fully martensitic. The presence of retained austenite may reduce the net growth. When tempering at 150-400°C, freezing treatments may be necessary to minimize retained austenite.

Machinability and Grindability in the annealed condition, CPM MagnaCut is easier to machine than 20CV and S30V. Similar grinding equipment and practices used for high-speed steels are recommended. “SG” type alumina wheels or CBN wheels have generally given the best performance with CPM steels.

DATA SHEET CRUCIBLE CPM® MagnaCut
Carbon 1.15%
Chromium 10.7%
Vanadium 4.00%
Molybdenum 2.00%
Niobium 2.00%
Nitrogen 0.20%

https://nsm-ny.com/wp-content/uploads/2021/07/CPM-MagnaCut-datasheet15.pdf