The purpose of this process is to heat the
Seamless Steel Pipe to a suitable temperature, so that the wear-resistant pipe is completely martensite and has excellent plastic deformation. The mechanical equipment used for heating is a dedicated continuous heat treatment furnace. After heating above the work hardening temperature, the surface layer is easily oxidized in the air to form oxide scale, which causes adverse damage to subsequent production and processing. In order to better prevent or reduce the air oxidation of wear-resistant pipes in the heat treatment furnace, a rare gas protection system is generally set in the heat treatment furnace, or the surface oxidation treatment of the pipe refers to the removal of the heated seamless steel pipe from the heat treatment furnace and put into the thermoforming mold. In this process, it is necessary to ensure that the wear-resistant tube is migrated to the mold as soon as possible. On the one hand, it is to better avoid air oxidation of seamless steel pipe at high temperature, and on the other hand, it is to better ensure wear resistance. The pipe is still at a high temperature when it is formed, and it has excellent plastic deformation. Stamping die and heat treatment: After the wear-resistant pipe is put into the mold, the stamping die should be formed on the seamless steel pipe immediately to avoid excessive temperature drop affecting the forming characteristics of the wear-resistant pipe. After molding, the mold shell should be closed and maintained at a pressure for a period of time. On the one hand, it is to better control the appearance of the part. The body of the body, producing excellent specification accuracy and physical properties. Studies have shown that at this stage, the minimum cooling rate of ordinary hot stamping mold stainless steel sheet to complete the transformation of martensite to austenite is 27~30 °C/s, so it is necessary to ensure that the cooling rate of the mold shell to the pipe exceeds this critical point. Post-treatment: After the molded parts are removed from the mold, some post-treatment must be carried out, such as pickling passivation or shot peening to remove the oxide scale on the surface of the part, and trimming and trimming the part. Because the compressive strength of hot metal stamping parts is too high, it cannot be processed by traditional trimming and punching methods, but must be carried out with laser equipment.
