[1] Low temperature tempering (150-250 degrees)
The structure obtained by low temperature tempering is tempered martensite. The purpose is to reduce the internal stress and brittleness of the quenched steel while maintaining the high hardness and wear resistance of the quenched steel, so as to avoid cracking or premature damage during use. It is mainly used for various high-carbon cutting tools, measuring tools, T9711.1 pipeline steel pipes, rolling bearings and carburized parts, etc. The hardness after tempering is generally HRC58-64.
[2] Medium temperature tempering (250-500 degrees)
The structure obtained by tempering at medium temperature is tempered troostite. Its purpose is to obtain high yield strength, elastic limit and high toughness. Therefore, it is mainly used for the treatment of various T9711.1 pipeline steel pipes and hot work dies, and the hardness after tempering is generally HRC35-50.
[3] High temperature tempering (500-650 degrees)
The structure obtained by high temperature tempering is tempered sorbite. It is customary to combine the heat treatment of quenching and high temperature tempering as quenching and tempering treatment. Its purpose is to obtain comprehensive mechanical properties with good strength, hardness, plasticity and toughness. Therefore, it is widely used in important structural parts such as connecting rods, bolts, gears and shafts of automobiles, T9711.1 pipeline steel pipes, and machine tools. The hardness after tempering is generally HB200-330.
Line Pipe Standard: API SPEC 5L - American Petroleum Institute Standard
Use:Oxygen, water and oil delivery pipes in the oil and gas industry
Main production steel pipe grades:B, X42, X52, X60, X65, X70 L245 L290 L320 L360 L390 L450 L485


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