After-forging heat treatment technique of CrMn steel

A post-heat treatment and process technology, which is applied in the field of post-forging heat treatment of CrMn steel, can solve the problems of failure, easy cracking and peeling

Active Publication Date: 2014-11-19
ZHANGJIAGANG CITY GUANGDA MACHINERY FORGING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] CrMn steel is a commonly used alloy die steel. CrMn steel is generally forged after smelting. After forging, heat treatment is required to improve the performance of raw materials. Under appropriate temperature and conditions, heat treatment can weld internal voids and improve CrMn The density of the steel controls the size and uniformity of the grains; the structure is strengthened by deformation or deformation-phase transformation, etc., and th...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] A kind of CrMn steel, after forging size is 2x1x1m, its heat treatment process comprises the following steps:

[0017] (1) Heat at a rate of 110°C / hour to 1055°C for solid solution, take it out after 1.5 hours of heat preservation, and use 32# mechanical oil for oil quenching, and cool to room temperature;

[0018] (2) Heat to 175°C at a rate of 60°C / hour, hold for 3 hours, heat to 780°C at a rate of 90°C / hour, hold for 1 hour, cool to 660°C, and hold for 1 hour;

[0019] (3) Heating to 780°C at a rate of 100°C / hour, holding for 1 hour, cooling the furnace to 655°C, and holding for 1.5 hours;

[0020] (4) Take out and cool to room temperature;

[0021] (5) Heat to 990°C at a speed of 100°C / hour, take it out after 1 hour of heat preservation, and use 32# mechanical oil quenching, heat to 160°C at a speed of 120°C / hour, take it out after 4 hours of heat preservation, and air cool to room temperature.

[0022] After testing, the mechanical properties of the CrMn steel de...

Embodiment 2

[0024] A kind of CrMn steel, after forging size is 2x0.8x0.6m, its post-forging heat treatment process, comprises the following steps:

[0025] (1) Heat at a rate of 120°C / hour to 1050°C for solid solution, take it out after 1 hour of heat preservation, and quench it with bright quenching oil, and cool to room temperature;

[0026] (2) Heating to 160°C at a rate of 80°C / hour, holding for 2 hours, heating to 770°C at a rate of 100°C / hour, holding for 0.5 hours, cooling the furnace to 650°C, and holding for 0.5 hours;

[0027] (3) Heating to 770°C at a rate of 100°C / hour, holding for 0.5 hours, cooling the furnace to 650°C, and holding for 1 hour;

[0028] (4) Take out and cool to room temperature;

[0029] (5) Heat to 1000°C at a speed of 100°C / hour, take it out after 0.5 hours of heat preservation, and quench it with bright quenching oil, heat it to 150°C at a speed of 100°C / hour, take it out after 3 hours of heat preservation, and cool it to room temperature in air.

[0030...

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PUM

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Abstract

The invention discloses an after-forging heat treatment technique of CrMn steel, which comprises the following steps: (1) heating to 1050-1060 DEG C to perform solid solution treatment, keeping the temperature for 1-1.5 hours, taking out, carrying out oil quenching, and cooling; (2) heating to 150-180 DEG C, keeping the temperature for 2-3 hours, heating to 770-780 DEG C, keeping the temperature for 0.5-1 hour, carrying out furnace cooling to 650-660 DEG C, and keeping the temperature for 0.5-1 hour; (3) heating to 770-780 DEG C, keeping the temperature for 0.5-1 hour, carrying out furnace cooling to 650-660 DEG C, and keeping the temperature for 1-1.5 hours; (4) taking out, and cooling in air; and (5) heating to 980-1000 DEG C, keeping the temperature for 0.5-1 hour, taking out, carrying out oil quenching, heating to 150-160 DEG C at the speed of 100-120 DEG C/hour, keeping the temperature for 2-4 hours, taking out and cooling in air. The multiplex heat treatment is utilized to improve the properties of the CrMn steel, so that the internal structure is dense and uniform and has high carbide dispersion degree on the premise of keeping high hardness and high wear resistance, and thus, the internal stress and brittleness are lowered, thereby avoiding cracking or early failure when the CrMn steel is in use; and the CrMn steel has favorable strength and toughness.

Description

technical field [0001] The invention belongs to a steel forging heat treatment process, in particular to a CrMn steel post-forging heat treatment process. Background technique [0002] CrMn steel is a commonly used alloy die steel. CrMn steel is generally forged after smelting. After forging, heat treatment is required to improve the performance of raw materials. Under appropriate temperature and conditions, heat treatment can weld internal voids and improve CrMn The density of the steel controls the size and uniformity of the grains; the structure is strengthened by deformation or deformation-phase transformation, etc., and the hardness, impact toughness, fatigue strength and wear resistance of CrMn steel are also increased by heat treatment. It has been improved to achieve the good comprehensive properties such as hardness, strength and plasticity required by the parts, but the CrMn steel cannot achieve the ideal effect after conventional heat treatment, and it is easy...

Claims

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Application Information

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IPC IPC(8): C21D8/00C21D6/00C21D11/00
Inventor 罗晓芳
Owner ZHANGJIAGANG CITY GUANGDA MACHINERY FORGING
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