工业纯铁与不锈钢炉中钎焊工艺及性能研究

Study on brazing furnace technology and properties of industrial pure iron and stainless steel joint

采用黄铜钎料对GDT30工业纯铁与1Cr18Ni9Ti奥氏体不锈钢进行炉中钎焊,利用场发射扫描电镜(FESEM)、X射线衍射仪(XRD)和显微硬度仪等研究了钎焊温度和保温时间对接头成型及组织和性能的影响。结果表明,在钎焊温度1050℃,保温时间15 min的条件下,能获得无缺陷的、性能良好的钎焊接头,四组工艺条件下未发现铜渗入不锈钢晶界。电工纯铁/过渡区/钎缝显微硬度变化平缓均匀,在不锈钢/界面区硬度达到最高值。钎缝中心区组织为α(Cu)+β′(CuZn)固溶体,电工纯铁侧扩散区和界面由铁素体组成,不锈钢侧扩散区和界面组织为奥氏体和β′(CuZn)固溶体。

GDT30 industrial pure iron and 1Cr18Ni9Ti austenitic stainless steel were brazed with brass filler metal in furnace.The effects of brazing temperature and holding time on the forming,microstructure and properties of the joints were investigated by field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD)and microhardness tester.The results show that the brazing joints without defects and with good performance can be obtained under the conditions of brazing temperature 1050℃and holding time 15 min.No copper is found to penetrate into the grain boundary of stainless steel under the four sets of process conditions.The microhardness of pure iron/transition zone/brazing seam changes gently and evenly,and the hardness of stainless steel/interface zone reaches the highest value.The central area of brazing joint is composed ofα(Cu)andβ′(CuZn)solid solution,and the diffusion area and interface of electrician pure iron are composed of ferrite.The diffusion zone and interface structure of stainless steel are composed of austenite andβ′CuZn electronic compounds.