大厚度F690超高强海工钢临界再热粗晶区组织脆化研究  

Study on Microstructure Embrittlement of Intercritically Reheated Coarse-Grain HAZ for Heavy-gauge Higher Strength Marine Engineering Steel F690

作　　者：张晓雪 汪晶洁 车马俊 崔强 赵晋斌 Zhang Xiaoxue;Wang Jingjie;Che Majun;Cui Qiang;Zhao Jinbin(Nanjing Iron and Steel Co.,Ltd)

机构地区：[1]南京钢铁股份有限公司

出　　处：《宽厚板》2018年第5期4-8,共5页Wide and Heavy Plate

摘　　要：采用Gleeble-3800热模拟试验机进行一次焊接热循环和二次焊接热循环模拟试验,研究100mm厚超高强海洋工程用钢F690焊接热影响区临界再热粗晶区的组织和性能特征。结果表明:大厚度超高强F690钢板在二次焊接热循环作用下,临界再热粗晶区(ICCGHAZ)生成大量M-A组织,由于这些M-A组织呈链珠状沿原始奥氏体晶界分布,严重恶化组织的低温韧性,导致热影响区局部脆化。因此,大厚度超高强海工钢不仅需要在成分设计时特别考虑焊接性能,而且还要在多层多道次焊接过程中严格控制焊接热输入量和层间温度,避免热影响区组织脆化现象。The microstructure and property characteristic of intercritically reheated coarse - grain heat - affected zone （ICCGHAZ） for 100 mm thick heavy - gauge higher strength marine engineering steel F690 are experimentally in- vestigated by single and double welding thermal cycle tests on Gleeble -3800 thermal simulator. The results show that blocky M - A constituent are formed at intercritically reheated coarse - grain heat - affected zone （ICCGHAZ） under the actions of double welding thermal cycle, which severely deteriorates the low temperature toughness and leads to local embrittlement in HAZ due to the M - A constituent distributed along the primary austenite grain boudary in the form of chain beads. Therefore, for heavy - gauge higher strength marine engineering steel, in order to prevent microstructure embrittlement at HAZ, it is not only necessary to pay special attention to the weldability, but also emply stringent con- trol on welding heat input and inter - pass temperature during muhiple layers and passes welding.

关 键 词：海工钢 F690 临界再热粗晶区(ICCGHAZ) 局部脆化区(LBZ) 

分 类 号：TG142.1[一般工业技术—材料科学与工程]