Tempering heat treatment process of high-strength steel

Abstract

The invention relates to a tempering heat treatment process and in particular relates to a tempering heat treatment process of high-strength steel. The process comprises the following steps: heating a material to 850-920 DEG C to be austenitized and furnace-cooling the material to the room temperature to be annealed after insulating the material for 3-5 hours to achieve the aim of tissue homogenization; heating the material to 850-920 DEG C to be austenitized and water-quenching the material to 200-260 DEG C after insulating the material for 3-5 hours; carrying out high-temperature tempering after insulating the quenched material for 2-5 hours at 590 DEG C, 610 DEG C, 630 DEG C, 650 DEG C and 670 DEG C respectively. The process has the effects that the method is unique; by controlling and adjusting the tempering and insulating temperatures, the impacts of the tempering heat treatment process on the low-temperature impact property of the high-strength steel are determined, the best tempering process parameters including the material strength and tenacity up to the standard are obtained and the comprehensive properties of the material used in the low-temperature environments are ensured to meet the requirements.

Description

technical field [0001] The invention relates to a tempering heat treatment process, in particular to a tempering heat treatment process for high-strength steel. Background technique [0002] General high-strength cast steel materials have high strength and poor toughness, especially under low temperature working conditions, the tendency of brittle fracture of the material will increase, and it is difficult to maintain the balance of strength and toughness at this time. At present, the repeatability and reproducibility of low temperature impact toughness of materials during heat treatment is very poor. In the early production process, there are often situations where the strength and impact properties cannot be satisfied at the same time. When the strength can meet the requirements, the low-temperature impact cannot meet the performance requirements, or when the low-temperature impact can meet the requirements, the strength is lower than the performance indicators. requireme...

AI Technical Summary

Problems solved by technology

[0002] General high-strength cast steel materials have high strength and poor toughness, especially under low temperature working conditions, the tendency of brittle fracture of the material will increase, and it is difficult to maintain the balance of strength and toughness at this time

At present, the repeatability and reproducibility of low temperature impact toughness of materials during heat treatment is very poor

In the early production process, there are often situations where the strength and impact properties cannot be satisfied at the same time. When the strength can meet the requirements, the low-temperature impact cannot meet the performance requirements, or when the low-temperature impact can meet the requirements, the strength is lower than the performance indicators. requirements, and the material -20°C impact and -40°C impact results are unstable, which greatly prolongs the test cycle, increases the cost of manufacturing, and restricts the development of enterprises

[0003] So far there is no way to overcome the above

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