临界退火温度对中锰TRIP钢组织和性能的影响

李岩,杜敬超,定巍,龚志华,潘红波

钢铁研究学报 ›› 2018, Vol. 30 ›› Issue (3) : 185-193.

钢铁研究学报 ›› 2018, Vol. 30 ›› Issue (3) : 185-193. DOI: 10. 13228/j.boyuan.issn1001- 0963. 20170128
材料研究

临界退火温度对中锰TRIP钢组织和性能的影响

  • 李岩1,杜敬超2,定巍2,龚志华2,潘红波3,4
作者信息 +

Influence of intercritical annealing temperature on microstructure and mechanical properties of medium Mn TRIP steel

  • LI Yan1,DU Jing- chao2,DING Wei2,GONG Zhi- hua2,PAN Hong- bo3,4
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文章历史 +

摘要

采用淬火热膨胀仪、扫描电镜、透射电镜、X射线衍射和拉伸试验机对0. 2C- 5Mn TRIP钢临界区相变行为、微观组织及力学性能进行了研究,并运用Factsage软件对0. 2C- 5Mn TRIP钢在临界区的相变热力学进行了计算,在此基础上讨论了临界区相变过程的特点。研究结果表明,临界区逆转奥氏体含量随着临界退火温度的升高而逐渐增加,逆转奥氏体中碳含量先增加后减少,Mn含量逐渐下降,逆转奥氏体热稳定性也逐渐下降。当临界退火温度为700℃时,在冷却过程中发生明显的马氏体相变;随着临界退火温度增加,渗碳体逐渐溶解,但由于相变时间较短,渗碳体无法完全溶解;当临界退火温度为600~675℃时,临界退火后的微观组织由铁素体、渗碳体和残余奥氏体构成。当临界退火温度为700℃时,临界退火后的组织由铁素体、残余奥氏体、马氏体以及少量未溶解的渗碳体构成;随着临界退火温度的升高,实验钢的工程应力- 应变曲线变化显著,在675℃退火3min后获得最佳的力学性能,抗拉强度为1138MPa,断后伸长率为23%。

Abstract

The transformation, microstructure and mechanical properties of the 0. 2C- 5Mn TRIP steel after intercritical annealing were investigated using dilatometer, scanning electronic microscopy (SEM), transmission electron microscopy(TEM), X- ray diffraction (XRD), and tensile testing machine. The phase transformation thermodynamics of the investigated steel after intercritical annealing was calculated by Factsage software and the characteristics of the transformation were discussed. The results show that the reversed austenite content increases with the increasing of the intercritical annealing temperature, the carbon content in reversed austenite firstly increases and then decreases, manganese content in reversed austenite decreases, which results in the decreasing of the thermal stability of reversed austenite. When the intercritical annealing temperature is 700℃, an obvious martensitic transformation occurs during the cooling process. With the increasing of intercritical annealing temperature, cementite is gradually dissolved, but it cannot be completely dissolved due to the short transformation time. When the intercritical annealing temperature is 600-675℃, the microstructure after intercritical annealing consists of ferrite, cementite and retained austenite. When the intercritical annealing temperature is 700℃, the microstructure after intercritical annealing consists of ferrite, retained austenite, martensite and a small amount of undissolved cementite. The engineering stress and strain curves of the investigated steel are significantly changed with increasing intercritical annealing temperature. At the same time, the optimal mechanical properties with tensile strength of 1138MPa and total elongation of 23% can be obtained after annealed at 675℃ for 3min.

关键词

中锰TRIP钢 / 相变 / 微观组织 / 力学性能 / Factsage

Key words

medium Mn TRIP steel / transformation / microstructure / mechanical properties / Factsage

引用本文

导出引用
李岩,杜敬超,定巍,龚志华,潘红波 . 临界退火温度对中锰TRIP钢组织和性能的影响[J]. 钢铁研究学报, 2018, 30(3): 185-193 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20170128
LI Yan,DU Jing- chao,DING Wei,GONG Zhi- hua,PAN Hong- bo,. Influence of intercritical annealing temperature on microstructure and mechanical properties of medium Mn TRIP steel[J]. Journal of Iron and Steel Research, 2018, 30(3): 185-193 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20170128

基金

国家自然科学基金;国家自然科学基金;内蒙古自然科学基金;内蒙古自然科学基金

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