45# seamless steel pipe is usually suitable for seamless steel pipe material, seamless steel pipe is divided into GB8162, GB8163 these two commonly used, but 45# seamless steel pipe is a common material of machining. 45# seamless steel pipe quenching and tempering is a dual heat treatment of quenching and high temperature tempering, which aims to make the workpiece have good comprehensive mechanical properties.
During quenching and tempering, the whole section of 45# seamless steel pipe is required to be hardened thoroughly, so that the microstructure of workpiece is mainly fine needle like quenched martensite.
By high temperature tempering, the microstructure of uniformly tempered sorbite is obtained. It is impossible for a small factory to carry out metallographic analysis for each furnace.
Generally, only hardness test is carried out. That is to say, the hardness of 45# seamless steel pipe after quenching must reach the quenching hardness of the material, and the 45# seamless steel pipe hardness after tempering shall be checked according to the requirements of the drawing.
