What is NM400 equivalent Indian standard

    
    Indian Standard (IS) 750 specification details the requirements for hardened steel (also known as “HARDO”). NM400 is a brand of hardened steel produced by Jfe Group, based in Japan. This steel is used in various industries, including aerospace and automotive, as a structural material and component parts.
    
    IS 750 specification covers the alloying elements, the post-weld heat treatment requirements, the hardness requirements, the mechanical properties requirements, and the acceptance tests of steel at wrought martensite. The alloying elements required are C (Carbon), Cr (Chromium), Mo (Molybdenum), Ni (Nickel), Si (Silicon), Mn (Manganese), and other additional elements, if required.
    
    The post-weld heat treatments required for NM400 are neither mandatory nor specified by IS 750. However, NM400 is usually processed by the annealing and tempering treatment of the weldments. This means that the welded parts can be subjected to a thermal cycle, usually for around 2 hours, at 560-650°C. After the parts are cooled, they are tempered at a temperature of 585-655°C, held there for around 8-12 hours and then cooled.
    
    The hardness test required for NM400 steel is the Vickers Hardness Test. This test is conducted to determine the hardness, and should meet the hardness requirement of 207-241 on the Vickers Hardness scale. This hardness should also be uniform throughout the steel component.
    
    The mechanical properties required for NM400 steel deposits are governed by the specifications in IS 750. These include tensile strength, yield strength, and elongation requirements. The tensile strength should be between 800-1100MPa, the minimum yield strength should be greater than 550MPa, and the elongation should be greater than 14%. These requirements are important in determining the suitability of a steel component for a specific application.
    
    The acceptance tests required for NM400 steel deposits are also specified in the IS 750 specification. These tests include the tensile test, bend test, and tensile-bend test. The tensile test is used to verify the tensile strength and elongation requirements. The bend test is used to check for any cracking or breakage that may occur due to bending or other deformations. The tensile-bend test is used to verify the strength and integrity of NM400 steel, when subjected to a combination of tensile and bending load.
    
    This is an overview of the requirements listed in the Indian Standard (IS) 750 specification for NM400 steel. The specification ensures that the steel produced is of a consistent quality and performance, and is suitable for its intended purposes.