According to the different performance requirements of
API 5L line pipes and the different tempering temperature, tempering can be divided into the following types:
1. Low temperature tempering (150-250°C)
The structure obtained by low temperature tempering is tempered martensite. Its purpose is to reduce the internal stress and brittleness of quenched steel while maintaining the high hardness and high 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, rolling bearings and carburized parts, etc. The hardness after tempering is generally HRC58-64.
2. Medium temperature tempering (250-500°C)
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 hot work molds, and the hardness after tempering is generally HRC35-50.
3. High temperature tempering (500-650°C)
The structure obtained by high temperature tempering is tempered sorbite. Traditionally, the heat treatment combining quenching and high temperature tempering is called quenching and tempering treatment, and its purpose is to obtain comprehensive mechanical properties with good strength, hardness, plasticity and toughness. Therefore, it is widely used in important structural parts of automobiles and machine tools, such as connecting rods, bolts, gears and shafts. The hardness after tempering is generally HB200-330.
Permanent Steel Manufacturing Co.,Ltd, as a professional API 5L
carbon steel tube supplier, integrates warehousing, sales, processing, and distribution. It specializes in the management of various seamless steel pipes, as well as the on-demand seamless steel pipes of special processes, special sizes and special materials. Custom-made products are used in various industrial fields such as engineering, coal mines, textiles, electric power, boilers, machinery, and military industries.
