MIL-A-12560H[MR) see attached
22.214.171.124 Forming. Forming after the final quenching and tempering
operations shall not be done except when authorized by the procuring activity.
MIL–A-46100 steel plate is a military spec armor steel exhibits high-hardness (HH). Surface hardness of this material is between 477 and 534 brinell. While the material can be formed, it is important to note that due to its ductile limitations, it should not be bent improperly. What we had on forming MIL–A-46100 was from ATI:
Cold forming can be performed with the proper techniques and suitable equipment in a highly controlled environment. Given the
high strength nature and material properties of ATI 500-MIL plate, set up should be thoroughly evaluated before cold forming.
Although cold forming is not recommended, it is possible. ATI 500-MIL plate up to 0.375" gauge has been successfully cold formed.
The following precautions should be taken when cold forming this material:
1. Grind edges, grind outside surface which will be in tension and grind to create round corners.
2. Use lubricant.
3. Nearly five times as much power is required compared with mild steel.
4. Forming across grain direction is preferred but not mandatory.
5. Allow for greater "spring-back" due to higher yield strength.
Hot forming is recommended with the following guidelines:
1. Plate should be heated to the 1550ºF to 1650ºF (843ºC to 899ºC) temperature range prior to forming.
2. To maintain ballistic quality, toughness, and metallurgical integrity, the temperature of the plate should
not exceed 1650ºF (899ºC.)
3. Grind edges and create round corners.
4. After forming allow steel to cool uniformly with unrestricted air flow (still air recommended) to the top and bottom of
plate until plate temperature is <300º F (149ºC.) Do not cool using water quenching or forced air cooling methods.
Steel will re-harden to approximately 500 BHN.