| 引用本文: | 徐彬,马成勇,李莉,齐彦昌,彭云.1 200 MPa级HSLA钢的SH-CCT曲线及其热影响区组织与性能[J].材料科学与工艺,2016,24(3):28-33.DOI:10.11951/j.issn.1005-0299.20160305. |
| XU Bin,MA Chengyong,LI Li,QI Yanchang,PENG Yun.SH-CCT diagram, microstructures and properties of heat-affected zone of a 1 200 MPa grade HSLA steel[J].Materials Science and Technology,2016,24(3):28-33.DOI:10.11951/j.issn.1005-0299.20160305. |
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| 摘要: |
| 为在工程应用中对焊接工艺的合理选取与制定提供理论和试验依据，采用焊接热模拟技术研究了800~500 ℃冷却时间(t8/5)对1 200 MPa级低合金高强钢焊接热影响区粗晶区(CGHAZ)显微组织和性能的影响.结果表明：t8/5为6~20 s时，该钢热影响区的粗晶区组织为板条马氏体，硬度为477~456 HV5；随着冷却时间的延长，组织中开始出现板条贝氏体，在t8/5为60 s时硬度下降到380 HV5；当t8/5为60~600 s时，粗晶区组织为板条贝氏体和粒状贝氏体，硬度为380~300 HV5；t8/5>600 s时粗晶区组织主要为粒状贝氏体，硬度为300~315 HV5.试验钢碳当量为0.626%，冷裂纹敏感系数为0.335%，说明其淬硬倾向较大，焊接热影响区容易产生裂纹.
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| 关键词: 焊接热模拟 低合金高强钢 焊接热影响区 显微组织 硬度 |
| DOI：10.11951/j.issn.1005-0299.20160305 |
| 分类号:TG142.7 |
| 文献标识码:A |
| 基金项目: |
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| SH-CCT diagram, microstructures and properties of heat-affected zone of a 1 200 MPa grade HSLA steel |
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XU Bin1,2,MA Chengyong2,LI Li1,QI Yanchang2,PENG Yun2
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(1.College of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093, China; 2.The Welding Institute, China Iron and Steel Research Institute Group,Beijing 100081,China)
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| Abstract: |
| To provide theoretical and experimental basis for the proper selection of welding parameters in engineering application,the effect of cooling time from 800 to 500 ℃ (t8/5) on the microstructure and properties of the coarse grained heat affected zone (CGHAZ) of a 1 200 MPa grade HSLA steel was investigated by using the thermal simulation tests. The results indicate that the microstructure of the CGHAZ consisted of lath martensite with hardness 477~456 HV5 as t8/5 is 6~20 s. With prolonging cooling time,the lath bainite forms in the steel,and the hardness decreases to 380 HV5 as the t8/5 is 60 s. As t8/5 is 60~600 s,it shows a microstructure of lath granular bainites with hardness 380~300 HV5. When t8/5 is longer than 600 s,the CGHAZ mainly shows a microstructure of granular bainite with hardness of 300~315 HV5. The carbon equivalent and cold cracking susceptibity coefficient of this steel is 0.626% and 0.335%,respectively,indicating that the harden quenching tendency is strong and the cold crack can easily form in the HAZ of the steel.
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| Key words: welding thermal simulation HSLA steel heat-affected zone microstructure hardness |
