焊后热处理对DH36钢焊接接头断裂韧性的影响

文中对DH36钢埋弧焊焊接接头进行了焊后热处理,并根据BS7448标准对焊缝和热影响区进行裂纹尖端张开位移CTOD测试,研究焊后热处理对断裂韧性的影响.结果表明,焊后热处理对焊缝断裂韧性的影响并不一定是好的效果,热处理后,焊缝δ值有的升高有的降低；焊后热处理对热影响区粗晶区的断裂韧性有不利影响,热处理后,热影响区粗晶区的δ值均有所下降.经过焊后热处理,90 mm厚焊缝试样的δ值略有下降,60mm厚焊缝试样的δ值明显升高；90mm厚热影响区试样的δ值明显下降,60mm厚热影响区试样的δ值略有下降.

Influence of post weld heat treatment on fracture toughness of DH36 steel welded joints

Based on the BS7448 standard,the crack tip opening displacement (CTOD) tests were conducted on the weld metal and heat-affected zone (HAZ) of DH36 steel joint,which was made with submerged arc welding (SAW) process and then followed by post weld heat treatment (PWHT),to investigate the influence of PWHT on fracture toughness. The results demonstrate that PWHT did not always produce positive effects on fracture toughness of weld metal. Especially,PWHT had negative influence on fracture toughness of HAZ with coarsened grains, and the CTOD values in coarsened HAZ decreased. After PWHT,the CTOD value of weld metal from 90 mm thick specimen slightly descended,while that from 60 mm thick specimen obviously increased. The CTOD value of HAZ from 90 mm thick specimen descended severely,while that from 60 mm thick specimen descended slightly.