Fire suddenly encountered in the process of vacuum heat treatment distortion

In recent years, with the auto parts heat treatment technology is more and more mature, the geometry precision of workpiece after heat treatment is more and more demanding. Quenching deformation of workpiece geometry precision of decline inevitably. Quench heating to 850 ~ 850 ℃, and high temperature tends to produce adverse effect, for example: produce distortion, etc. Moulded type vacuum quenching also called pressure quenching, is the effective measure to reduce the quenching distortion and widely applied in automobile industry.

Vacuum quenching distortion is the most common problems in the process of heat treatment, for batch production of bearings and gears, control of quenching distortion is to improve the inner quality and the service life of the product. For materials for carburizing steel (such as carburizing bearing steel G20CrNi2MoA) or gear with low alloy steel (18 crmnti, etc.), finished product requirements must be carburized layer thickness, good surface toughness of high hardness of the core requirements. The die quenching technology is to prevent quenching distortion, direct and effective measures for promoting the voltage qualification rate.

Against distortion of problems faced in the process of vacuum quenching, there is a kind of effective control of the distortion of the die quenching technology and equipment, may, by way of control force size, cycle and adjust the structure of the quenching mould and size, control the flow of cooling fluid, flow pattern and flow, etc., to control the distortion process, reduce the distortion of the workpiece, on the premise of meet the requirements of quenching, the mold and machine tool portfolio as a whole, provides the quenching process of die quenching technology and equipment, while guarantee the hardness and metallographic requirements, maintain the consistency of the quenching workpiece, the quenching quality control in the best level, and put into industrial application, the comprehensive reduce the quenching distortion.

Moulded vacuum quenching technology of 0 cr17ni4cu4nb steel in the process of implementation in solid solution and solid solution plus aging under the two states of two different nitriding process test, this paper discusses the process temperature, ammonia decomposition rate, the original organization layer depth of the material, the influence of the microstructure and properties after nitriding. The results showed that after solid solution effect, 0 cr17ni4cu4nb steel nitriding after nitriding layer depth, surface hardness and the core hardness is basically the same, can consider to use directly after solid solution nitriding; 540 ℃ after nitriding is better than 480 ℃ after nitriding performance.