2.25Cr1Mo0.25V耐热钢与304不锈钢AA-TIG焊接接头组织及性能研究

Study on the microstructures and properties of AA-TIG welding joint of 2.25Cr1Mo0.25V heat-resistant steel and 304 stainless steel

采用电弧辅助活性AA-TIG焊对2.25Cr1Mo0.25V耐热钢和304不锈钢管进行异种钢材焊接,并对其焊接接头的组织、硬度及力学性能进行分析。结果表明,使用AA-TIG焊能够一次性焊透2.25Cr1Mo0.25V耐热钢和304不锈钢,得到成形良好的焊接接头。焊缝处无裂纹等焊接缺陷,焊缝处各元素在焊缝水平方向分布均匀。在靠近两侧母材的焊缝区,Cr、Fe、Ni元素有一定的梯度,但无明显偏聚。焊接接头两边的母材区硬度值较低,在焊缝区域硬度达到最大,焊缝区域的硬度波动范围在400~489 HV之间,最终拉伸试样都断在304母材上,得到的平均拉伸强度为406 MPa,最大的抗拉强度为542 MPa。

The dissimilar steels of 2.25Cr1Mo0.25V heat-resistant steel and 304 stainless steel pipe were weld-ed by arc-assisted active AA-TIG welding,and the microstructure,hardness and mechanical properties of the welded joints were analyzed.The results show that the AA-TIG welding can weld through 2.25Cr1Mo0.25V heat-resistant steel and 304 stainless steel at one time,and get a well-formed welding joint.There are no welding defects such as cracks at the weld seam,and all elements at the weld seam are evenly distributed in the horizontal direction of the weld seam.In the weld zone near the base metal on both sides,there is a certain gradient of Cr,Fe,and Ni elements,but there is no obvious segregation.The hardness values of the base metal areas on both sides of the welded joint are relatively low,reaching their maximum in the weld area.The hardness fluctuation range in the weld area is between 400 and 489 HV,and the final tensile specimens are all broken on the 304 base metal.The average tensile strength obtained is 406 MPa,and the maximum tensile strength is 542 MPa.