Analysis of decarburization in the heat treatment of anchor bolts

The process of producing an anchor bolt is relatively complicated, and only bolts that go through multiple processes and require each process can be basically qualified. If you want to meet the actual pre-design specifications and standards, you still need to go through a lot of harsh inspections, as well as efficient logistics storage, transportation and proper assembly, and finally you can make full use of the actual role of an anchor bolt. There is a process in the production and processing process of anchor bolts to improve the comprehensive process performance of fastening parts, that is to say, heat treatment process. This process has a very important impact on standard parts such as anchor bolts, especially the quality of anchor bolts. With the development direction of the stage, after entering the 1990s, the rotary heat treatment automatic production line with maintenance effect has already taken the leading role. In addition to the extremely good airtightness of the furnace in the heat treatment line, the temperature and basic process parameters are controlled by computers very accurately, and the equipment failure alarm and display functions are also readily available. In the process of heat treatment, some oxidized gas will be generated from the outside of the furnace. According to a series of chemical changes and the reflection of rust on the surface of the bolt, the bolt raw material itself will be decarburized. Maijin found through technical research that the degree of decarburization of medium-carbon aluminum alloy steel is more severe than that of carbon steel, and the faster decarburization temperature is between 700 and 800 degrees Celsius. The main reason is that the small particles adhered to the surface of the stainless steel wire dissolve the substance very quickly under certain conditions. If the furnace gas is not well controlled, it will also cause screw decarburization errors. When the bolts are formed by cold heading, the heat-treated decarburization layer of the original raw materials not only still exists, but is also extruded to the top of the bolt pipe thread. At this time, the surface of the bolts that must be heat-treated loses the pre-design strength requirements. At that time, the process performance of the high wear-resistant anchor screws will be greatly reduced.