Manufacturing process of low-carbon high-strength bolt for track

Abstract

The invention relates to a manufacturing process of a low-carbon high-strength bolt for a track. The process comprises the following steps of: (1) selecting a material, namely selecting low-carbon alloy steel with chemical component 20MnTiB; (2) thermally rolling the alloy steel into coil rod steel, and performing cold drawing treatment to achieve the size of the rod part of the bolt; (3) formingthe head and the rod part of the bolt by adopting local heating and forging; (4) machining external threads of the bolt; (5) quenching the whole bolt; (6) tempering the whole bolt; and (7) performingblackening treatment. The process has the advantages that: because the tempering temperature belongs to a tempering low temperature, power consumption is saved; meanwhile, water-soluble quenching liquid is adopted in low-carbon high-strength bolt quenching, so pollution of quenching oil to the environment is avoided; and the adopted low-carbon alloy steel material is 300 yuan per ton lower than the conventional material, so the production cost is reduced.

Description

[0001] technical field [0002] The invention relates to a bolt manufacturing process, in particular to a low-carbon high-strength bolt manufacturing process for crawler tracks. Background technique [0003] At present, the high-strength bolts for crawler tracks are grade 12.9 bolts, the hardness requirements are 39-43HRC, the mechanical properties are above 1275Mpa in tensile strength, and above 1147Mpa in yield strength. In order to meet the above performance requirements, the material used in the existing technology is 35CrMo medium carbon alloy steel. The process is a quenching and tempering process. The quenching temperature is 850-880°C, heating and proper heat preservation, and then quenching in rapid quenching oil. The tempering temperature is between 450-500°C and fully tempered to obtain tempered wire. The heat treatment process of celite, this process consumes a lot of energy, and the problem of quenching oil pollution to the environment is becoming more and more ...

AI Technical Summary

Problems solved by technology

[0003] At present, the high-strength bolts for crawler tracks are grade 12.9 bolts, the hardness requirements are 39-43HRC, the mechanical properties are above 1275Mpa in tensile strength, and above 1147Mpa in yield strength. In order to meet the above performance requirements, the material used in the existing technology is 35CrMo medium carbon alloy steel. The process is a quenching and tempering process. The quenching temperature is 850-880°C, heating and proper heat preservation, and then quenching in rapid quenching oil. The tempering temperature is between 450-500°C and fully tempered to obtain tempered wire. The heat treatment process of celite, the energy consumption of this process is large, and the problem of the pollution of the quenching oil to the environment is becoming more and more prominent