How much smoothness of the inner hole of the cold drawn seamless steel pipe
can be achieved? This is mainly based on the customer's product requirements. In the field of hydraulic steel pipes, the inner hole smoothness of the cold drawn seamless pipe can reach Rz2.0mm/M. This precision requires many manufacturers to reach Yes, but Permanent Steel Manufacturing Co.,Ltd
can, so why can PMC say that? What aspects of the finish of the inner hole of the cold drawn seamless pipe are affected?
The main influencing factors of the inner hole finish of cold drawn seamless steel pipe:
The perforation experience of the manufacturer is immature, the perforation temperature is uncontrollable, the perforation equipment is short, and the uneven heating of the round steel causes a large temperature deviation between the inside and outside of the steel pipe, forming pits, pits, and peeling, etc., and the finish is not good. PMC has an elongated perforation furnace, and the steel pipe is heated evenly.
2. Cold drawn mold
There are defects in the cold drawing mold itself, resulting in poor internal finish of the seamless pipe finished product. PMC uses professional customized precision molds with high precision, and the inner and outer surfaces of the finished product after cold drawing are of good quality.
Due to strict environmental protection requirements in recent years, many manufacturers do not have the pickling process, and can only get outside processing without professional experience, but there is no accumulation of data on the pickling time of steel, so let the processing plant process it at will. As a result, the internal impurities of the cold drawn seamless pipe cannot be completely cleaned, or the excessive acid forms pits, pits and other problems. PMC has a fully enclosed environmentally-friendly pickling tank since its establishment. With more than ten years of data accumulation, there are different pickling methods and times for different steel grades, and the inner hole finish can be guaranteed.
4. Production process
Another important reason that affects the smoothness of the inner hole of the cold drawn seamless steel pipe (astm a106
) is the deformation of the seamless steel pipe during the cold drawing process. The amount of deformation mainly depends on the number of cold drawing passes. The smaller the amount of deformation, the higher the finish, but the cost will also increase. Some small manufacturers will reduce the number of processing passes in order to make more profits, but PMC is based on quality and produces according to the actual needs of customers, and the product quality is visible.