Cast iron series mould material thermal treatment method capable of acquiring controllable and uniform rigidity

A heat treatment method and mold material technology, applied in the field of heat treatment, can solve the problem of not mentioning the heat treatment method of cast iron mold materials, etc., and achieve the effect of good hardenability

Inactive Publication Date: 2010-01-20
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of the above-mentioned technology is that: only the heat treatment process of LD steel mold materials is mentioned, and how to obtain the heat treatment method of cast iron mold materials with controllable and uniform hardness is not mentioned

Method used

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  • Cast iron series mould material thermal treatment method capable of acquiring controllable and uniform rigidity

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Obtain heat treatment for cast iron mold target hardness 33HRC, material is HT300

[0027] (1) Normalizing pretreatment: the material HT300 is placed in a vacuum annealing furnace, and the vacuum degree is pumped to 1×10 -1 Pa, then preheat to 900°C, hold for 180 minutes to austenitize, leave the vacuum furnace and air cool to obtain a uniform balanced structure;

[0028] (2) Oil cooling and quenching: Put the workpiece processed in step (1) into the vacuum oil quenching furnace, and the vacuum degree is 1×10 -1 Pa, then raise the temperature to 600°C at a heating rate of 10°C / min, hold for 50 minutes, then raise the temperature to 890°C at a heating rate of 5°C / min, leave the vacuum furnace after holding for 100 minutes, and quench with oil cooling to obtain horse body tissue;

[0029] (3) Put the workpiece processed in step (2) into the vacuum tempering furnace, and the vacuum degree is 1×10 -1 Pa, and then tempered three times with variable temperature:

[0030] ...

Embodiment 2

[0035] Obtain heat treatment for cast iron mold target hardness 45HRC, material is QT600

[0036] (1) Normalizing pretreatment: material QT600 is placed in a vacuum annealing furnace, and the vacuum degree is pumped to 1×10 -1 Pa, then preheat to 920°C, hold for 180 minutes to austenitize, and air-cool after leaving the vacuum furnace to obtain a uniform balanced structure;

[0037] (2) Oil cooling and quenching: Put the workpiece processed in step (1) into the vacuum oil quenching furnace, and the vacuum degree is 1×10 -1 Pa, then raise the temperature to 620°C at a heating rate of 10°C / min, hold for 50 minutes, then raise the temperature to 890°C at a heating rate of 5°C / min, leave the furnace after holding for 100 minutes, and quench by oil cooling to obtain martensite organize;

[0038] (3) Put the workpiece processed in step (2) into the vacuum tempering furnace, and the vacuum degree is 1×10 -1 Pa, and then tempered three times with variable temperature:

[0039] Tem...

Embodiment 3

[0044] Heat treatment to obtain cast iron mold target hardness 55HRC, material is MoCr cast iron

[0045] (1) Normalizing pretreatment: the material MoCr cast iron is placed in a vacuum annealing furnace, and the vacuum degree is pumped to 1×10 -1 Pa, then preheat to 950°C, hold for 180 minutes to austenitize, and air-cool after leaving the vacuum furnace to obtain a uniform balanced structure;

[0046] (2) Oil cooling and quenching: Put the workpiece processed in step (1) into the vacuum oil quenching furnace, and the vacuum degree is 1×10 -1 Pa, then raise the temperature to 650°C at a heating rate of 10°C / min, keep it warm for 50 minutes, then raise the temperature to 900°C at a heating rate of 5°C / min, keep it for 100 minutes, take it out of the furnace, and quench it with oil cooling to obtain martensite organize;

[0047] (3) Put the workpiece processed in step (2) into the vacuum tempering furnace, and the vacuum degree is 1×10 -1 Pa, and then the vacuum furnace is t...

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Abstract

The invention relates to a heat treatment method which can obtain the cast iron die material, the hardness of which is controllable and uniform. The heat treatment method has the steps as follows: in the first step, the cast iron die material is put in a vacuum firing furnace for prewarming until the temperature reach 900 to 950 DEG C, and is air-cooled after being taken out of the vacuum firing furnace after austenization; in the second step, a workpiece is put in the vacuum firing furnace, is heated until the temperature reaches 600 to 650 DEG C, is processed through heat preservation, is again heated until the temperature reaches 890 to 900 DEG C, then is taken out of the vacuum firing furnace after being processed through heat preservation, and is quenched in an oil cooling manner, so as to obtain a martensite structure; in the third step, the workpiece is put in the martensite structure for three temperature variations and tempers; wherein, in the first temper, the temperature ranges from 230 to 600 DEG C, and the heat preservation and the oil cooling are executed; in the second temper, the temperature ranges from 230 to 600 DEG C, and the heat preservation and the oil cooling are executed; in the third second temper, the temperature ranges from 250 to 600 DEG C, and the heat preservation and the oil cooling are executed. By the heat treatment method, the hardness of the obtained cast iron die can be controlled between 33HRC and 55HRC in a deterministic manner, the hardness fluctuation can be controlled within 10 percent, and the effect that the whole die is hardened is achieved.

Description

technical field [0001] The invention relates to a method in the technical field of heat treatment, in particular to a method for heat treatment of cast iron mold materials capable of obtaining controllable and uniform hardness. Background technique [0002] With the rapid development of my country's automobile industry, the domestic automobile cold stamping die industry has also developed rapidly. Due to factors such as cost, cast iron is generally used as the material for cold stamping dies for automobiles, such as MoCr cast iron, nodular cast iron and gray cast iron. However, these cast iron mold materials generally have low hardness, which makes it difficult to control the quality of stamping parts, and the mold life is short. In order to solve this problem, surface treatment methods are usually used to strengthen the surface hardness of the mold, such as surface flame heat treatment, surface laser heat treatment, surface chrome plating treatment, or other surface modifi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D5/00C21D1/28C21D1/18
Inventor 陈新平蒋浩民于忠奇李淑慧鲍平侯英岢
Owner SHANGHAI JIAO TONG UNIV
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