Special heat treatment process for large high-alloy die

Abstract

The invention discloses a special heat treatment process for a large high-alloy die. The special heat treatment process comprises the steps of preheating for the die, first-phase quenching treatment, second-phase quenching treatment, pre-cooling, rapid cooling and the like, wherein the ratio of a first-phase quenching treatment time, a second-phase quenching treatment time and a heating time therebetween is (80+ / -5): 5: (15+ / -5). According to the special heat treatment process disclosed by the invention, a two-section heating and quenching method is adopted, thus the high red hardness, high wear resistance and high corrosion resistance of a surface are guaranteed while an enough high strength of the whole die is ensured; relatively thick martensites are only limited on a surface layer and the ratio of the martensites occupying the section of the whole die is not greater than 20% after die quenching, therefore, the overall impact toughness of the die is high, and the condition of cleavage fracture is not easily caused, thus the scrapping of the die is effectively avoided or reduced; and a total high-temperature heating time of the die can be greatly shortened compared with that of a traditional mode, therefore, energy can be saved and equipment loss can be reduced.

Description

technical field [0001] The invention belongs to the technical field of heat treatment process, and in particular relates to a special heat treatment process of a large high-alloy mold. Background technique [0002] In the metal material deformation processing industry in the field of machinery manufacturing industry, almost all working molds must undergo heat treatment, quenching and tempering. But no matter how it is quenched and tempered, the quenching process is always the top priority in each process of the entire heat treatment process, and it is particularly important to determine the heating method of the quenching process. In the traditional heat treatment quenching heating method, although the selection of temperature value is very elegant, the process design generally selects the quenching heating temperature parameter according to the material grade and service conditions of the mold and the current status of the equipment. The quenching heating modes are basical...

AI Technical Summary

Problems solved by technology

The traditional heat treatment quenching heating mode commonly used above is not easy to find any problems for many smaller molds, but there are relatively big problems for large molds over 300kg or over 600kg, especially for those molds that require In terms of service conditions with high wear resistance and high red hardness on the surface, the high alloy steel mold heat-treated by the above-mentioned traditional quenching heating mode is not satisfactory in wear resistance, or the deformation and cracking of the mold are very serious, and the scrap amount of the mold is relatively large

This forces people to choose medium and low-end heating and quenching methods for mold heat treatment to solve the problem of large mold cracking and scrapping. This method has a certain effect, but the production efficiency of forged products is low. The workload of rework is very huge. When the production volume is large, the progress of producing molds and forged products often cannot keep up, and the comprehensive benefits are not ideal.

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