论文部分内容阅读
采用气电立焊及热模拟试验研究了原油储罐用高强钢大热输入焊后热影响区、尤其是粗晶热影响区的组织与性能。结果表明,TMCP高强钢大热输入焊后粗晶区组织粗大,以板条贝氏体为主,距熔合线0.5 mm处冲击吸收功最低(77 J),冲击值完全高于标准要求(47 J)。Nb0.026%TMCP钢热影响区中导致冲击韧性严重下降的脆性M-A组元含量极少,这与钢中固溶的Nb含量较少有关,固溶Nb能降低γ-α转变温度,促使粒状贝氏体形成;Nb0.014%RQ+T钢降低了Nb含量,同时添加少量Ti,形成Ti、Nb复合添加,热影响区M-A组元含量很少,冲击韧性接近TMCP钢。
Gas-electric vertical welding and thermal simulation tests were carried out to study the microstructure and properties of heat-affected zone (HAZ) after high temperature heat input of high strength steel for crude oil storage tank, especially in the coarse heat-affected zone. The results show that the coarse grain of coarse TMCP high strength steel after heat input welding is coarse and coarse with lath bainite, the lowest impact absorbed power (0.5 J) at the fusion line is 77 J, the impact value is completely higher than the standard (47 J). Nb0.026% TMCP steel heat-affected zone lead to a serious decline in the impact toughness of the brittle MA content of very little, which is the content of Nb in solid solution with less steel, Nb can reduce the γ-α transformation temperature, to promote granular Bainite; Nb0.014% RQ + T steel reduced Nb content, while adding a small amount of Ti, forming Ti, Nb composite addition, heat affected zone MA content is very small, impact toughness close to TMCP steel.