Explanation of heat treatment and precision of machining process

There are already a lot of knowledge about mechanical processing, but for us, this knowledge is not enough to be comprehensive, and there will always be omissions. Therefore, we need to supplement and update the knowledge so that we can grasp more updated knowledge in time. , So as to achieve a comprehensive and detailed understanding of this aspect of mechanical processing.

Content 1: Heat treatment in parts machining process Heat treatment in parts machining process can generally be divided into two types: preliminary heat treatment and final heat treatment. Preliminary heat treatment: Its purpose is to improve mechanical properties and eliminate internal stress in order to prepare for the final heat treatment, which generally includes annealing, normalizing, quenching and tempering, and aging treatment. Preparatory heat treatment is generally performed after rough machining. Final heat treatment: its purpose is to improve the hardness and wear resistance of the parts, including quenching, carburizing, nitriding and other processes, generally after semi-finishing and before finishing. Content 2: The accuracy of machining The accuracy of machining is mainly reflected in the following aspects, which are dimensional accuracy, geometric shape accuracy and mutual position accuracy. The geometric shape accuracy includes roundness, straightness, and flatness. Position accuracy includes parallelism, perpendicularity, and coaxiality. Content 3: What are the methods to obtain machining accuracy? Dimensional accuracy: There are mainly methods such as trial-cutting method, adjustment method, sizing method and automatic control method. Geometric shape accuracy: There are mainly trajectory method, forming method and generative method. Mutual position accuracy: There are mainly direct installation methods, alignment installation methods and fixture installation methods.