焊材匹配对低温弯管焊缝组织和低温冲击韧性的影响  

Effect of Welding Material Matching on Microstructure and Impact Toughness of Low Temperature Bend Pipe

作　　者：包志刚 马佼佼[1,2] 李超 田小江[1,2] 张君 赵西岐[1,2] BAO Zhigang;MA Jiaojiao;LI Chao;TIAN Xiaojiang;ZHANG Jun;ZHAO Xiqi(Chinese National Engineering Research Center for Petroleum and Natural Gas Tubular Goods,Baoji 721008,Shaanxi,China;Steel Pipe Research Institute of Baoji Petroleum Steel Pipe Co.,Ltd.,Baoji 721008,Shaanxi,China)

机构地区：[1]国家石油天然气管材工程技术研究中心,陕西宝鸡721008 [2]宝鸡石油钢管有限责任公司钢管研究院,陕西宝鸡721008

出　　处：《焊管》2020年第12期7-11,共5页Welded Pipe and Tube

基　　金：中国石油天然气集团公司科技支撑项目“中俄东线站场低温环境用Φ1422 mm X80钢管、感应加热弯管研究与现场焊接技术研究”(项目编号FK80219KI)。

摘　　要：针对低温弯管生产过程中焊缝金属韧性降低的问题,采用不同焊材匹配获得了3种不同成分的低温热煨弯管焊缝试样,并采用热模拟试验机研究了加热温度对热煨弯管焊缝组织和性能的影响。结果显示,3种热煨弯管在焊态条件下,焊缝的组织均以针状铁素体为主,且具有较高的低温冲击功,经模拟加热后,焊缝组织转变为针状铁素体、多边形铁素体和粒状贝氏体的混合组织,且随着加热温度的升高,针状铁素体减少,低温冲击功降低。随着Mn和Ni含量的增加,在较低加热温度条件下,焊缝组织中针状铁素体增加,低温冲击功较高,但在较高加热温度条件下,焊缝组织则转变为粗大的回火粒状贝氏体,低温冲击功降低。结果表明,为得到较好的焊缝低温冲击性能,加热温度宜在925℃以下。In view of the problem that the toughness of weld metal is reduced in the production process of low temperature bending pipe,three kinds of weld samples of low temperature hot-bending pipe with different compositions are obtained by the different welding materials matching.The effect of heating temperature on the microstructure and properties of the weld of the hot-bending pipe was studied by thermal simulation test machine.The results show that under the welding condition,the microstructure of the weld of the three kinds of hot-bending pipe is dominated by acicular ferrite and has high low temperature impact energy.After simulated heating,the microstructure of the weld is transformed into a mixture of acicular ferrite,polygonal ferrite and granular bainite,and with the increase of heating temperature,the acicular ferrite decreases and the low temperature impact energy decreases.With the increase of Mn and Ni contents,the acicular ferrite in the weld microstructure increases and the low temperature impact energy is higher at lower heating temperature.But under the condition of high heating temperature,the weld microstructure transforms into coarse tempered granular bainite,and the low temperature impact energy decreases.The results show that the heating temperature should be below 925°C to obtain better low temperature impact performance of weld.

关 键 词：热煨弯管 低温冲击韧性 焊材匹配 加热温度 

分 类 号：TG423[金属学及工艺—焊接]