摘要
采用焊接热模拟技术研究了焊接热循环对X120管线钢焊接热影响区的组织和性能的影响。结果表明,经过一次热循环峰值温度1300℃后,随着t8/5的增加,韧性显著下降,发生严重脆化;当t8/5不变,二次热循环峰值温度为600℃和1200℃时,韧性得到明显改善;当二次热循环峰值温度为800℃时,在原奥氏体晶界处形成明显的"链状"结构的网状组织,韧性有所下降;而当二次热循环峰值温度为1000℃时,局部脆化现象严重,这与冷却时获得含有粗大M-A岛状组织的粒状贝氏体有关。
The effects of welding thermal cycle on the microstructure and mechanical properties of heat-affected zone （HAZ） of XI20 pipeline steel was studied by using welding thermal simulation. The experimental results indicate that when the peak temperature of thermal cycle is 1300 ℃, toughness value drops severely with the increase of t,5. While t8/5 is invariable, it can obtain good toughness after second thermal cycle at peak temperature 600℃ and 1200 ℃. When the peak temperature of the second thermal cycle is 800℃, it forms net microstructure with chain structure in grain boundary and toughness decreases. When the peak temperature of the second thermal cycle is 1000℃, local brittleness with the large M-A islands in granular bainite appears during cooling process.
出处
《热加工工艺》
CSCD
北大核心
2010年第1期20-23,共4页
Hot Working Technology
关键词
焊接热循环
局部脆化
X120管线钢
韧性
welding thermal cycle
local frangibility
X 120 pipeline steel
toughness
