Common methods for local quenching of mechanical parts
Maybe many friends have not heard of the concept of local quenching. After all, most people don't pay attention to the knowledge of these industries, but many friends who are engaged in mechanical construction must be familiar with it. Let's take a look at the related topics together with Kehua. information. Local quenching and heat treatment knowledge - surface local quenching and hardness testing method Surface local quenching heat treatment, usually by induction heating or flame heating, when processing the local hardness of the parts, the parts are usually marked on the drawings. The location and part of the local quenching heat treatment The hardness value, the hardness test of the part should be carried out in the specified area. The hardness testing instrument can use the Rockwell hardness tester to test the HRC hardness value. If the heat treatment hardened layer is shallow, the surface Rockwell hardness tester can be used to test the HRN hardness value. The main technical parameters are surface hardness, local hardness and effective hardened layer depth. Vickers hardness tester can be used for hardness testing, Rockwell or surface Rockwell hardness tester can also be used. The selection of the test force (scale) is related to the depth of the effective hardened layer and the surface hardness of the workpiece. There are three durometers involved here. Vickers hardness tester is an important method to test the surface hardness of heat-treated workpieces. It can use a test force of 0.5-100kg to test the surface hardened layer as thin as 0.05mm thick. It has the highest accuracy and can distinguish the small hardness of the workpiece surface. difference. What are the detection methods for local quenching? In addition, the depth of the effective hardened layer is also detected by a Vickers hardness tester. Therefore, it is necessary to have a Vickers hardness tester for units that perform surface heat treatment or use a large number of surface heat treated workpieces. The surface Rockwell hardness tester is also very suitable for testing the hardness of surface quenched workpieces. There are three scales for the surface Rockwell hardness tester to choose from. Various case-hardened workpieces with an effective hardening depth of more than 0.1mm can be tested. Although the accuracy of the surface Rockwell hardness tester is not as high as that of the Vickers hardness tester, it has been able to meet the requirements as a detection method for quality management and qualification inspection of heat treatment plants. Using the surface Rockwell hardness tester, batches of surface heat-treated workpieces can be quickly and non-destructively tested piece by piece. This has important implications for metalworking and machine building plants. When the surface heat treatment hardened layer is thick, the Rockwell hardness tester can also be used. When the thickness of the hardened layer is 0.4-0.8mm, the HRA scale can be used, and when the thickness of the hardened layer exceeds 0.8mm, the HRC scale can be used. Partial quenching is a method that is often used in many large-scale machinery manufacturing industries, and it is in a very high temperature state, so you must pay attention to safety issues in the production process. If you want to know more, then pay attention to Kehua it.