A thermal processing method for improving the mechanical properties of medium carbon steel

A technology of hot working and carbon steel, applied in the field of metal material science, which can solve the problems of limited mechanical properties, uneven structure, and inability to meet the requirements of working conditions for medium carbon steel

Active Publication Date: 2019-11-29
本溪聚赢新材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantage of medium carbon steel is poor hardenability, and the dispersion strengthening effect of granular carbides distributed on the ferrite matrix after quenching and tempering treatment is insufficient, resulting in low strength of medium carbon steel, which cannot meet some high strength requirements. In order to maximize the performance of medium carbon steel due to the requirements of working conditions, it is of practical significance to explore new methods to improve the mechanical properties of medium carbon steel.
[0003] At present, the commonly used methods are mainly to add alloying elements to steel and thermal processing (including: deformation, heat treatment, etc.). Although the effect of adding alloying elements is good, there are strict control of the process system, high cost, and uneven structure. Phenomenon
However, the use of thermal processing to improve the mechanical properties of medium carbon steel is limited.

Method used

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  • A thermal processing method for improving the mechanical properties of medium carbon steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] The experimental material is 35 medium carbon steel, and the medium carbon steel includes the following elements in mass percentage: C 0.36%, Mn 0.56%, Si 0.32%, P 0.027%, S 0.025%, and the balance is iron.

[0033] A medium-carbon steel sample with a size of Φ8×10mm is subjected to high-temperature and high-pressure heat treatment on a CS-ΙΙB six-sided top press, with a pressure of 6GPa, a temperature of 900°C, and a holding time of 10 minutes; to room temperature to obtain pretreated medium carbon steel;

[0034] The pretreated medium carbon steel was heated up to 500°C at a rate of 50°C / min under a pressure of 6GPa, and after holding the temperature for 30 minutes, the power was turned off and the pressure was maintained and cooled to room temperature with the furnace.

[0035] The mechanical properties of medium carbon steel obtained by high temperature and high pressure heat treatment and low temperature and high pressure heat treatment are shown in Table 1.

Embodiment 2

[0037] The experimental material is 45 medium carbon steel, and the medium carbon steel includes the following elements in mass percentage: C 0.46%, Mn 0.51%, Si 0.28%, P 0.031%, S 0.028%, and iron in the balance.

[0038] The size of the sample and the experimental equipment are the same as in Example 1. The pressure of the high-temperature and high-pressure heat treatment is 2GPa, the temperature is 860°C, and the holding time is 15min. Then, the power is turned off and the pressure is kept and the furnace is cooled to room temperature to obtain a pretreated medium carbon steel;

[0039] The pretreated medium carbon steel was heated up to 600°C at a rate of 50°C / min under a pressure of 2GPa, and after 60min of heat preservation, the power was turned off and the pressure was maintained to cool down to room temperature with the furnace.

[0040] The mechanical properties of medium carbon steel obtained by high temperature and high pressure heat treatment and low temperature and...

Embodiment 3

[0042] The experimental materials, sample size and experimental equipment are the same as in Example 2. The pressure of high temperature and high pressure heat treatment is 4GPa, the temperature is 900°C, and the holding time is 10min. ;

[0043]The medium-carbon steel was heated up to 500°C at a rate of 50°C / min under a pressure of 4GPa, and after holding for 40 minutes, the power was turned off and the pressure was maintained to cool down to room temperature with the furnace.

[0044] The mechanical properties of medium carbon steel obtained by high temperature and high pressure heat treatment and low temperature and high pressure heat treatment are shown in Table 1.

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PUM

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Abstract

The invention provides a hot working method for improving mechanical properties of medium carbon steel, and relates to the technical field of metal material science. The hot working method comprises the step: the medium carbon steel is sequentially subjected to high-temperature and high-pressure heat treatment and low-temperature and high-pressure heat treatment. The medium carbon steel is subjected to high-temperature and high-pressure heat treatment to obtain a fine martensite structure with the high dislocation density, dislocation provides more positions for precipitation of carbide in thesubsequent low-temperature and high-pressure heat treatment process, and the number of precipitated carbide particles is increased; and through low-temperature and high-pressure heat treatment, the diffusion coefficient of atoms is decreased under the high pressure effect, thus the number of the precipitated carbide particles is large, the precipitated carbide particles are not prone to growing up and thus are finer and more dispersed, the dispersion enhancement effect is enhanced, and the hardness and strength of the medium carbon steel are increased. Compared with the same process normal-pressure heat treatment, the hardness value and compression yield strength of the medium carbon steel treated through the hot working method are increased by 10.00-12.12% and 10.77-14.33% correspondingly.

Description

technical field [0001] The invention relates to the field of metal material science and technology, in particular to a thermal processing method for improving the mechanical properties of medium carbon steel. Background technique [0002] Medium carbon steel has low cost, good thermal processing technology, and has good strength, toughness and plasticity after quenching and tempering treatment (quenching + high temperature tempering). It can be used to make shaft and gear parts and has been used in machinery manufacturing and other aspects. be widely used. However, the disadvantage of medium carbon steel is poor hardenability, and the dispersion strengthening effect of granular carbides distributed on the ferrite matrix after quenching and tempering treatment is insufficient, resulting in low strength of medium carbon steel, which cannot meet some high strength requirements. In order to maximize the performance of medium-carbon steel due to the requirements of working condi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D7/13C21D6/00C22C38/02C22C38/04
Inventor 刘建华赵晓洁金珊张丁心于淼杨英慧程奔王岳峰
Owner 本溪聚赢新材料科技有限公司
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