Production of hot-rolled seamless tube perforation is the most important step of deformation, its mission is to wear a solid tube rolled into a hollow tube. According to the structure and deformation characteristics piercing process of piercing machine can be divided into conventional perforating method: oblique piercing, piercing push and pressure perforation, piercing and oblique most widely used, the shape of the rotary piercing machine rolls have roll, bacteria formula (cone) and disc are three type piercing mill rolling mill rolls for use in small, while large units using bacteria type piercer rolls. Disc punch seldom used. Regardless of the roll shape how, in order to ensure the tube bite and achieve piercing process has perforated cone (roll inlet cone), grinding mill cone (roll outlet cone) and roll rolled strip (excessive portion of the inlet cone and the outlet cone between )composition.


Piercer roll use a combination of rollers and the structure of the roller sleeve, both of direct interference or a combination of interference plus key combination. Thus, when the roll scrap, rollers can continue to reuse, to reduce tooling costs. Small punch roller material more choice of 45 or 40Cr, quenched and tempered. Large punch rollers multi 42CrMo, quenching and tempering. Roll material manufacturers currently using more complex, some manufacturers use 45, 55 and so on forging high-quality carbon structural steel. Some manufacturers use 50Mn, 65Mn, 70Mn, 70Mn2Mo, 60CrMnMo alloy cast or forged; hardness range requirements are inconsistent, and some require HB180-220, some require HB220-260. In order to increase the bite of the large perforated roller general processing depth of 0.8 ~ 1.2mm mesh pattern of the inlet cone.


Comprehensive domestic and foreign manufacturers of material selection and usage, I think: the choice of casting roll punch 50Mn, 60CrMnMo carbon steel and other materials more appropriate, one has good strength and wear resistance, the second is applied to each rolling kinds of material pipe. Hardness Control in HB200-240 more reasonable.