不锈钢多孔管与致密管钎焊接头组织与性能的研究

Research of Structure and Properties of Joints Brazed Between Stainless Steel Porous Tube and Dense Tube

采用镍基钎料BNi-7真空钎焊316L不锈钢多孔管和304不锈钢致密管,对其焊接接头的显微组织结构进行了分析,研究了钎焊温度对焊接接头组织结构、抗拉强度和最大孔径的影响。结果表明,在钎焊过程中,不锈钢多孔管与致密管中的Fe和Cr溶解进了熔融的钎料里,与钎料内的合金元素相融合并向母材扩散,形成一定的焊缝组织和化学成分,完成牢固的冶金焊接。随着钎焊温度的提高,焊接接头的抗拉强度先升高后降低,而焊接接头的最大孔径则是先降低后升高。较佳的钎焊温度为980℃,在该温度下获得的样件在具有良好抗拉强度(240MPa)的同时,兼具适合的最大孔径(3.87μm)。

The microstructure properties of vacuum brazing joints between 316L stainless steel porous tube and 304 stainless steel dense tube which using nickel based filler BNi-7 were analyzed. The effects of brazing temperature on the microstructure,tensile strength and maximum aperture were studied. The results show that during the brazing process, Fe and Cr elements of stainless steel porous tube and dense tube dissolve in the melt brazing filler,and the alloy elements in the brazing filler fuse and spread into base material, so the microstructure and chemical composition form at last, which finishes the firm metallurgical welding. The tensile strength of the joints firstly increases and then reduces with brazing temperature increasing; maximum aperture firstly reduces and then increases with brazing temperature increasing. The optimal Brazing temperature is 980℃, the maximum aperture reaches 3.87 μm and the tensile strength reaches 240 MP at 980℃.