不同氮含量焊丝熔化极气体保护焊高氮钢的微观组织与力学性能

为研究不同氮含量焊丝对高氮钢焊缝组织性能的影响,采用自制的0.46[N]、0.61[N]、0.84[N]3种不同氮含量焊丝进行高氮钢熔化极气体保护焊焊接工艺试验.测试分析3种成分焊丝焊缝的固氮效果、气孔倾向、微观组织及力学性能.结果表明:随着焊丝氮含量的增加,焊缝氮含量升高,气孔倾向也增大;3种焊丝焊缝组织均由奥氏体+...

Microstructure and Mechanical Property of High-nitrogen Steel with GMAW Welding Wires with Different Nitrogen Contents

In order to study the structures and properties of high-nitrogen steel welds with different nitrogen content welding wires, three kinds of welding wires with different nitrogen contents of 0.46［N］,0.61［N］ and 0.84［N］ were used in gas metal arc welding (GMAW) tests of high-nitrogen steel, and the nitrogen fixation effect, porosity, microstructure and mechanical properties of the welds were tested and analyzed. The results show that, as the nitrogen content of welding wire increases, the nitrogen content of weld increases, and the porosity tendency increases; the microstructures of three welding wires are composed of austenite and ferrite, the microstructure of weld is mainly determined by the solidification mode of weld, which is determined by the joint action of various alloying elements in the weld; and the mechanical properties of welds are mainly affected by the content and distribution of ferrite. The higher the ferrite content and the distribution along the grain are, the higher the hardness and strength of the weld are, and the worse the toughness is. When the weld solidification mode is A or AF, the nitrogen content of the weld is higher, the tensile property of the weld is better. The pore defect mainly affects the impact toughness of the weld, and the increase in pores reduces the impact toughness of the weld.