去应力退火对P355NL1钢焊接接头组织及性能的影响

Effect of stress relief annealing treatment on microstructure and properties of P355NL1 steel welded joints

对比研究P355NL1钢MAG焊接接头去应力退火前后的微观组织和基本力学性能,结果表明,通过MAG焊接方法可获得外观良好的焊接接头。去应力退火处理对焊接接头的焊缝、热影响区和母材的微观金相组织无明显影响。去应力退火处理对焊接接头的拉伸性能、断后伸长率和弯曲性能影响不大,但接头硬度有一定程度的降低。去应力退火接头焊缝冲击功变化不大,母材和热影响区的冲击功有一定程度的提高。综合来看,去应力退火处理对P355NL1钢MAG焊接接头的组织及基本力学性能无明显影响,能够保证接头具有良好的使用性能。

The microstructure and mechanical properties of P355NL1 steel MAG welded joints before and after stress relief annealing treatment were compared.The results show that a welded joint with good appearance could be obtained by the MAG welding method.The stress relieving annealing treatment has no obvious effect on the microstructure of the weld,heat-affected zone and base metal of the welded joints.The stress relief annealing treatment has little effect on the tensile properties,breaking elongation and bending properties of the welded joints,but the hardness of the joint reduces to a certain extent.The impact absorption energy of the stress relief annealing joint weld has little change,while the impact absorption energies of the base material and heat-affected zone have a certain degree of improvement.On the whole,the stress-relieving annealing treatment has no significant influence on the microstructure and mechanical properties of the P355NL1 steel MAG welded joints,which can ensure the good service performance of welded joints.