To process and produce a high-strength bolt, the process is a very complex project. It has to go through multiple and complicated processes, and strictly ensure that each process is a high-strength bolt before it can be considered as basically qualified.To meet the pre-design standards, more rigorous inspections, as well as reasonable storage, transportation and correct installation, can play the true role of a high-strength bolt.
High-strength bolts, bolts
One of the high-strength bolt manufacturing processes is to improve the comprehensive mechanical properties of fasteners, which is the heat treatment process.This process has a very important influence on the internal quality of high-strength bolts, such as fasteners, especially high-strength bolts.
With the development of the times, after entering the XNUMXs, the protective continuous heat treatment production line has occupied a dominant position.In addition to the good sealing performance of the furnace, the temperature and process parameters of the quenching and tempering line are very accurate by computer control, and the equipment failure alarm and display functions are also readily available.In the whole process of quenching and tempering heat treatment, some oxidizing gas will be brought from the outside of the furnace. Through a series of chemical changes and the surface rust of the high-strength bolts, the decarburization of the high-strength bolt material will occur.The degree of decarburization of medium-carbon alloy steel is more serious than that of carbon steel, and the decarburization temperature is between XNUMX and XNUMX degrees Celsius.The main reason is that the objects attached to the surface of the steel wire decompose compounds very quickly under certain conditions. If the continuous mesh belt furnace gas control is not good, it will also cause the screw to be decarburized excessively.When high-strength bolts are formed by cold heading, the annealed decarburized layer of the original material not only still exists, but also is extruded to the top of the high-strength bolt thread. At this time, the surface of the high-strength bolt that needs to be quenched is not available With the pre-designed hardness requirements, the mechanical properties of high-strength bolts will be greatly reduced at this time.