Thermal treatment method for thick die steel

Abstract

The invention belongs to the technical field of die steel and particularly relates to a thermal treatment method for thick die steel. The thermal treatment method for thick die steel comprises the steps that steel ingots are subjected to quenching heating, the tapping temperature is 800-900 DEG C, and the hoisting time is 2-4 min; air cooling is conducted during hoisting; and the quenching process is conducted after completion of hoisting. According to the thermal treatment method for thick die steel, the problem of hardenability of die steel of 700-900 mm is mainly involved. The quenching quality is improved by making the reasonable field quenching thermal treatment process.

Description

technical field [0001] The invention belongs to the technical field of die steel, and in particular relates to a heat treatment method for thick gauge die steel. Background technique [0002] The characteristics of large forgings are: large shape and heavy weight, high quality requirements during production, only single piece and small batch production, and long production cycle and strict technical conditions. In my country's current heavy equipment manufacturing industry, there is a great demand for large-scale forgings, and the quality requirements are also high, especially all kinds of high-strength and high-precision forgings still need to be imported, which has become the development trend of my country's heavy equipment manufacturing industry. one of the bottlenecks. [0003] The production of large forgings has to go through many processes from smelting, ingot casting, forging, post-forging heat treatment to performance heat treatment, and each process affects the qu...

AI Technical Summary

Problems solved by technology

[0005] In the actual production process, for large mold steel modules with a thickness greater than 700mm, impermeability during quenching is prone to occur, resulting in the appearance of pearlite structure, which in turn leads to problems such as insufficient hardness and uneven hardness distribution after tempering, which affects polishing and polishing. Performance

[0006] The publication number is "CN105695703A", and the title of the invention is "A Die Steel Heat Treatment Process". It discloses a two-fire direct heat treatment process method of 7Cr7Mo2V2Si high-strength and toughness cold-work die steel preparatory heat treatment and quenching and tempering. From the parameters introduced Look, only the hardness and wear resistance of the mold steel have some effect, but it is difficult to achieve the same cooling rate control in the internal and external heat treatment process of the material, and it is difficult to guarantee the uniformity of structure and performance

[0007] The application number is "200610049263.7", the title of the invention is "a new type of chromium steel mold steel and its heat treatment process", which discloses a manufacturing method of Cr8Mo2V1Si mold, and then briefly describes its heating temperature and heat preservation after three-fire heating Time parameters, it is difficult to reflect the control of quenching speed, and the guarantee of control uniformity is not reflected

[0008] The application number is "201410721290.9", and the title of the invention is "A 3Cr2Mo Die Steel Heat Treatment Process", which discloses a 3Cr2Mo die steel heat treatment process operation steps, which also utilizes the early high-temperature annealing plus quenching and tempering, and carburizing processes. Classified as a heat treatment process of two-fire or three-fire heating, the focus is to improve the surface thermal hardness and wear resistance, and the uniformity control and internal and external differences cannot be reflected and realized.

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