| 摘要: |
| 针对首次应用到核电上的SA508-3钢,在Gleeble1500D热模拟机上,采用膨胀法测定了SH-CCT曲线,获得了焊接工艺特征参数t8/5从3.75~20000 s范围内的焊接热影响区组织变化规律.结果表明,获得全部马氏体相变的冷却时间为15 s,全部贝氏体相变的冷却时间60 s8/5≤3000 s,全部铁素体和珠光体相变的冷却时间为6000 s;当t8/5≤100 s时,焊接热影响区硬度高于350 HV,存在淬硬和裂纹敏感性;当t8/5≥20000 s时,焊接热影响区硬度小于母材硬度,易出现软化现象. |
| 关键词: 核电SA508-3钢 冷却速度 焊接连续转变冷却曲线 裂纹敏感性 |
| DOI： |
| 分类号: |
| 基金项目:国家科技重大专项子课题(2009ZX04014-064-05) |
|
| Analysis on continuous cooling transformation curves of simulated heat affected zone for SA508-3 steel in nuclear power |
|
CHI Luxin1,2, MA Yonglin2, XING Shuqing2, ZHAO Yongtao2, CHEN Furong1, CHEN Zhongyi2
|
|
1.School of Materials Science and Engineering, Inner Mongolia University of Technology, Huhhot 010051, China;2.School of Material and Metallurgy, Inner Mongolia University of Science and Technology, Baotou 014010, China
|
| Abstract: |
| The SA508-3 steel used in nuclear power was used to determine continuous cooling transformation(SH-CCT) diagram of simulated heat affected zone(HAZ) by thermal expansion method on Gleeble 1500D thermal simulation testing machine,and the microstructure characteristics of HAZ at t8/5 from 3.75 s to 20 000 s were investigated.It was found that the microstructures were changed much from the base metal because of the influence of the cooling time(t8/5).When the t8/5 is less than 15 s,the phase transformation to obtain all martensite happens,the cooling time range to get all the bainite is from 60 s to 3 000 s,and if all the ferrite,and pearlite can be obtained if the t8/5 is more than 6 000 s.The hardness of HAZ is higher than 350 HV and there are harden quenching tendency and the crack sensitivity when the t8/5 is less than 100 s,softening phenomena easily happens and the hardness of HAZ is lower than that of the base metal when the t8/5 is more than 20 000 s.The cold cracking can be avoided only at the proper preheating temperature. |
| Key words: SA508-3 steel cooling rate continuous cooling transformation curves crack sensitivity |
