BNi-2真空钎焊不锈钢钎缝的相变规律研究

用差热分析、电子探针和金相分析等方法对用BNi 2钎料真空钎焊不锈钢 (1Cr1 8Ni9Ti)钎缝的相变规律进行了研究 ,并以Fick第二扩散定律为基础 ,对钎焊过程中硼元素的扩散系数进行了计算。研究结果表明 ,硼是影响钎缝组织和重熔温度的主要元素 ,延长钎焊时间或进行焊后扩散处理可以大大改善钎缝的综合性能。通过理论计算得出了在规定钎焊工艺条件下钎缝中不出现低熔化合物相的临界钎焊间隙与焊接时间的关系式 ,计算结果与试验结果吻合较好 ,计算精度优于 6%。

INVESTIGATION OF PHASE CHANGE RULES IN STAINLESS STEEL JOINT BRAZED WITH Bni-2 FILIER METAL

The phase change rules in 1Cr18Ni9Ti stainless steel joint brazed in vacuum with BNi 2 filler metal are investigated by the use of differential thermal analysis, electron probe and microstructure analysis. The diffusion coefficient of boron in brazing beam is calculated during brazing process by means of Fick second diffusion law. The boron is a main element affecting both microstructure and remelting temperature of the joint. The synthetic property of the joint can be improved by the way of extending brazing time and thermal treatment after brazing. The correlative formula between the critical gap disappearing intermetallic compounds in brazed beam and the brazing time is gained. The calculating result goes well with testing one. The calculating errors are less than 6%.