Different tempering temperatures are needed according to different requirements on the performance of API 5L line pipes. Tempering methods can be divided into three following types according to different temperatures.

1. Low-temperature tempering (150-250°C)

The first one is called low-temperature tempering. The structure obtained by low-temperature tempering is tempered martensite. It aims to reduce the internal stress and brittleness of the quenched steel while maintaining high hardness and high wear resistance of the quenched steel. So as to avoid cracking or premature damage during use. Low-temperature tempering is mainly used for making 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)

Then we will introduce the second method, medium temperature tempering. The structure obtained by medium temperature tempering is tempered troostite. Tempered troostite is designed 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 last tempering method is high-temperature tempering. The structure obtained by high-temperature tempering is tempered sorbate. 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.

ADTOMall, as a professional API 5L steel pipe supplier, specializes in the field of various steel pipes. Any requirements about steel pipe, please contact us directly.