Improvement of process for eradicating crack of roller

Many rollers with diameter no more than φ11mm cracked after heat treatment,with analyzing the organi- zation before heat treatment,it is found that the reason of causing crack is the excessive thermal stress when harden- ing rollers,by way of improving the technical parameter of heat treatment and decreasing the thermal stress,harden- ing crack was avoided .In this way,the aim of increasing production and practising economy were realized.