What is the cause of cracking of carburized 20 Cr steel in heat treatment well furnace?

There are many reasons for cracking. First, the material is wrong, especially the content of P and S is high, which is easy to crack. Second, the shape of the workpiece is unreasonable. Third, there is a problem with the carburizing process, and the carbon potential is too high and there is no diffusion, which leads to cracking. Fourthly, the quenching process is unreasonable, the cooling time is too long and the cooling speed is too fast. Fifth, tempering is not timely. I don't know what your problem is, so solve it yourself.