摘要
由于Q420钢冶炼时加入V、Ti、Nb等强烈碳化物形成元素,对焊缝性能造成不良影响,使其焊接性能不够稳定。与Q345普通低合金钢相比,Q420低合金高强度钢焊接难度大,焊接技术要求高,应制定严格的焊接工艺施焊。通过采用焊接热影响区最高硬度试验及斜Y型坡口焊接裂纹试验,结果表明:Q420B钢焊前可不预热,焊后也不需采用任何热处理工艺。但结合Q420B钢材的韧脆转变温度,当环境温度低于0℃时,应进行焊前预热150℃,以避免产生冷裂纹。
The weldability of steel Q420 is not satble because it has strong carbide forming element such as V,Ti ,Nb. Compared with low-alloy steel Q345, welding for low-alloy steel Q420 has high requirements. The maximum hardness test of heat-affected zone and Y slit cracking test show that steel Q420B need not has welding procedures such as preheating and post-heating treatment. However, considering ductile-brittle of steel Q420B, when temperature below 0℃, the steel must be preheat to 150 ℃ to prevent cold crack.
出处
《江西电力》
2012年第3期24-26,共3页
Jiangxi Electric Power
