激光清洗对SMA490BW钢接头表面应力及腐蚀的影响

Effect of laser cleaning on surface stress and corrosion of SMA490BW steel welded joint

为提高耐候钢焊接质量,将皮秒脉冲激光清洗技术引入到耐候钢焊接的清洗中,并研究了皮秒脉冲激光清洗对SMA490BW耐候钢焊接接头抗应力腐蚀性能的影响.X射线残余应力测试试验结果表明,激光清洗后试样表面残余拉应力增加130~200 MPa,不利于应力腐蚀性能的提高.但周期浸润腐蚀试验证明,激光清洗使试件表面的耐蚀性明显提高,这有利于提高接头的抗应力腐蚀性能.最后,通过三点弯应力腐蚀试验证明,激光清洗提高了耐候钢接头的抗应力腐蚀性能.其原因为激光清洗使试样表面形成微米级(0.8~1.2μm)紧密堆积的柱状颗粒,提高了试件表面的耐蚀性大于表面残余拉应力带来的影响.

In order to ensure high quality weathering steel welding,we introduce picosecond pulse laser cleaning technology into welded joint cleaning.This paper studied the effect of picosecond pulsed laser cleaning on stress corrosion resistance of SMA490BW weathering steel welded joints.Xray residual stress test shown that:The residual stress on the surface of the specimens after laser cleaning increased 130~200 MPa,which was not conducive to the performance of stress corrosion.But,the cyclic corrosion test proved that:The corrosion resistance of the specimen surface has been improved by laser cleaning,which is helpful to the stress corrosion resistance of the joint.Finally,the three-point bending stress corrosion test proved that:Laser cleaning can improve the stress corrosion resistance of the weathering steel joint.The reason is that the laser cleaning makes the surface formed micron scale(0.8~1.2μm)tightly packed columnar particles,which improved the corrosion resistance more than the influence of the residual tensile stress.