Quenching and tempering treatment: The ERW shell is tempered after high temperature tempering, which is called quenching and tempering treatment. High temperature tempering refers to tempering between 500-650 °C. Quenching and tempering can greatly adjust the performance of ERW shell and material, and its strength, plasticity and toughness are good, and it has good comprehensive mechanical properties. . The tempered sorbite is obtained after the tempering treatment. The tempered sorbite is formed of tempered martensite and is magnified 500 to 600 times under an optical microscope. It is characterized by the distribution of carbides in the ferrite matrix. It is also a tempering structure of martensite, a mixture of ferrite and granular carbide. At this time, the performance of the ERW is substantially free of carbon supersaturation in the ferrite, and the carbide is also a stable carbide. It is a balanced tissue at room temperature.




ERW casing tempering is a combination of high temperature tempering, tempering and low temperature tempering.


High temperature tempering: 500 ° C ~ 650 ° C


Medium temperature tempering: 300 ° C ~ 450 ° C


Low temperature tempering: 150 ° C ~ 250 ° C