AN APPROACH TO ROLL SHAFT FRACTURE IN RESPECT TO Ф108mm THREE-ROLL PIERCING MILL

The article gives analyses concerning roll shaft fracture happening on the three-roll piercing mill. Based on the experiments on such aspects as dimensions of the shaft critical section, shaft heat-treatment process, etc., which were made without changing the mill housing. It is concluded that the 40Cr steel made roll shaft can completely meet the requirements of normal production provided that it is designed and heat-treated properly.