论文部分内容阅读
采用焊接热模拟技术研究了焊接热循环对细晶组织09CuPCrNi钢热影响区粗晶区(CGHAZ)显微组织和性能的影响。结果表明,在800~500℃冷却时间t8/5≤8 s时,该钢CGHAZ组织为贝氏体和少量马氏体。随着t8/5延长,在原奥氏体晶界上逐渐析出先共析铁素体,当t8/5>18 s时,显微组织由大量铁素体和珠光体组成,且原奥氏体晶粒明显粗化,先共析铁素体含量增加。在-20℃和0℃下,t8/5对冲击吸收功影响较小,在-40℃时,随着t8/5延长,冲击吸收功下降显著,而且随着t8/5延长,CGHAZ硬度逐渐下降,但硬度值均高于母材,焊接热影响区相对于母材未出现软化倾向。
The effect of welding thermal cycle on the microstructure and properties of the CGHAZ in the heat affected zone of the fine-grained 09CuPCrNi steel was studied by using the welding thermal simulation technique. The results show that the microstructure of CGHAZ is bainite and a small amount of martensite at the cooling time of 800 ~ 500 ℃ for t8 / 5≤8 s. With the extension of t8 / 5, pro-eutectoid ferrite gradually precipitated on the original austenite grain boundaries. When t8 / 5> 18 s, the microstructure consisted of a large amount of ferrite and pearlite, and the former austenite Significant coarsening of the grain, pro-eutectoid ferrite content increased. At -20 ℃ and 0 ℃, t8 / 5 had little effect on the impact absorption energy. At -40 ℃, the impact absorption energy decreased significantly with the increase of t8 / 5. With the increase of t8 / 5, CGHAZ hardness gradually increased But the hardness values are higher than the base metal, HAZ relative to the base material does not appear softening tendency.