齿盘堆焊开裂后二次补焊对产品质量的影响

Influence of Secondary Repair-welding on Quality of Some Fluted Discs with Surfacing Welding Fissure

针对高硬度、高耐磨堆焊焊条的应用特点,研究了ZG32Cr06调质态堆焊工艺和补焊工艺以及其对基体材质组织的影响,探讨了堆焊裂纹形成的内在规律,分析了该工件焊接裂纹补焊的可能性以及补焊后对原组织的影响,并分析了堆焊及补焊裂纹形成的原因。研究发现,堆焊硬化层组织内应力很高,熔合线非常窄,承受剪应力的能力弱。堆焊熔池温度、冷却速度、堆焊层气体含量是堆焊裂纹产生的3个主要原因。二次裂纹的产生主要发生在一次堆焊工艺冷却速度较快、内应力较大的齿盘上。

To the question of the practical features of surfacing welding electrode, the process of surfacing welding and the influence on parental material of ZG32Cr06 hardening and tempering state surfacing welding were researched including it＇s influence on original structure after repair-welding. The internal law and the formation of welding fissure were also dis cussed. The probability of repair welding,the influence on primary structure and the cause of the welding crack were ann lyzed. The result showed that the innerstress of the structure of the hardening surface is extremely high,the weld interface areas are narrow,and the capability to endure shearing strength is weak. The molten temperature, the cooling velocity and the gas content are the three main reasons for welding fissure. The generation of the secondary fissures mainly developed in some fluted discs of cooling velocity faster and the innerstress larger.