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以8.0mm厚的高氮钢板为试验材料,采用Nd:YAG激光-熔化极活性气体保护焊(Metal Active Gas,MAG)电弧复合焊接方法,研究了单一成分活性剂(TiO_2,B_2O_3,Cr_2O_3)对高氮钢激光-电弧复合焊焊缝组织和性能的影响。研究表明,活性剂能增加焊缝组织的δ-铁素体数量、使晶粒细化、减小奥氏体的晶枝,对焊缝组织有改善作用。添加活性剂Cr_2O_3的焊缝组织变化显著,出现异金属夹杂现象;活性剂TiO_2、B_2O_3和Cr_2O_3都能使焊缝区硬度有所提高,使熔合区硬度有所降低,其中活性剂B_2O_3作用下的焊缝熔合区的硬度最小。加活性剂的复合焊焊接接头抗拉强度均比无活性剂复合焊焊接接头的抗拉强度低,抗拉强度的大小顺序为无活性剂>活性剂B_2O_3>活性剂Cr_2O_3>活性剂TiO_2,拉伸断口均为韧窝断口形貌。
The high-nitrogen steel plate with 8.0 mm thickness was used as experimental material. The Nd: YAG laser arc welding process was used to study the effect of single component activator (TiO 2, B 2 O 3, Cr 2 O 3) Effect of Laser and Arc Composite Welding on Structure and Properties of High Nitrogen Steel. The results show that the active agent can increase the amount of δ-ferrite in the weld microstructure, refine the grains and reduce the crystal grains of the austenite, which can improve the microstructure of the weld. The microstructure of the weld joint with active agent Cr_2O_3 changed obviously, and the heterogeneous inclusions appeared. The hardness of the weld zone increased with the active agent TiO_2, B_2O_3 and Cr_2O_3, and the hardness of the weld zone decreased. The effect of the active agent B_2O_3 Weld weld zone hardness minimum. The tensile strength of composite welded joint with active agent is lower than that of passive composite welded joint, and the order of tensile strength is inactive agent> active agent B_2O_3> active agent Cr_2O_3> active agent TiO_2 Broken mouth are dimple fracture appearance.