Heat treatment method of welding pipe mill

Quenching process is currently the most widely used welding pipe processing process, let’s get to know it .

It is known for its high processing efficiency and good quality of processed welded pipes. The lifespan of a roller mainly depends on its internal performance and working force, including strength and hardness. To ensure sufficient strength of the roller, the main consideration is from the material of the roller; Hardness usually refers to the hardness of the working surface of the roller, which determines the wear resistance of the roller and to a certain extent, the service life of the roller. Reasonable material selection and heat treatment methods can meet the hardness requirements of the roller.

Quenching process is the embodiment of the machining process of welded pipe and roller. To understand the processing technology of welded pipe rolling machines, we must first understand the quenching process. After rough and semi precision turning, the roller needs to undergo quenching and low-temperature tempering before precision turning.

The purpose of quenching is to:

• 1. Change the microstructure of the rolling mill by transforming the spherical pearlite after withdrawal into tempered martensite and a small amount of residual austenite, thereby improving the surface hardness and wear resistance of the rolling mill;

• 2. Obtain sufficient strength and toughness;

• 3. Extend the service life of the roller.

After quenching, there may be slight deformation of the roller, so precision machining should be carried out after annealing.

After quenching, a large amount of internal stress is generated in the organization due to rapid cooling, which is prone to cracking. After tempering, the internal stress can be eliminated to prevent cracking, as well as the quenched martensite and residual austenite in the quenched organization.