Quenched and tempered: erw casing quenched after the high temperature tempering known as quenching and tempering treatment.High temperature tempering refers to tempering between 500-650 ° C. Quenchingand tempering can make the performance of erw casing, material to a largedegree of adjustment, its strength, plasticity and toughness are better, withgood comprehensive mechanical properties. After tempering treatment to gettempered sorbite. Tempered sorbite is formed by tempering martensite and ismagnified by more than 500 to 600 times under an optical microscope microscope.It is characterized by the distribution of carbides in the ferrite matrixCarbon body) pellets of the composite organization. It is also a temperingorganization of martensite, a mixture of ferrite and granular carbides. At thispoint the performance of erw casing in the ferrite has been basically no carbonsupersaturation, carbide is also a stable carbide. At room temperature is abalanced organization.

ERW casing tempering is high temperaturetempering, tempering and low temperature tempering three categories.
High temperature tempering: 500 ℃~ 650 ℃
Medium temperature tempering: 300 ℃~ 450 ℃
Low temperature tempering: 150 ℃~ 250 ℃