This specification, in conjunction with the general requirements for steel heat treatment covered in AMS 2759, establishes the requirements and procedures for three classes of gas, vacuum and liquid carburizing and related heat treatment of parts fabricated from carburizing grade steels. It does not cover pack carburizing.

Classification:

Parts to be carburized shall be processed to meet the requirements of one of the following classes:

Class 1: Case depth and case hardness shall be as specified. Subsurface case hardness shall be in accordance with Table 1. Surface carbon shall be 0.70 to 1.00%. Retained austenite shall not exceed 10%. Intergranular carbides shall be scattered and discontinuous and shall not be evident in more than 40% of the grain boundaries.

Class 2: Case depth and case hardness shall be as specified. Subsurface case hardness shall be in accordance with Table 1. Surface carbon shall be 0.75 to 1.10%. Retained austenite shall not exceed 20%. Continuous carbide network shall not be evident in more than 80% of the grain boundaries.

Class 3: Case depth and case hardness shall be as specified.

If no class is specified, parts shall be processed to meet the requirements of Class 2.

Types:

Type 1: Gas and vacuum carburizing

Type 2: Liquid (salt bath) carburizing

If no type is specified, Type 1 shall be used.

Safety - Hazardous Materials:

While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved.