不锈钢焊条熔滴过渡形态与焊接冶金学的相关性

Correlation between metal transfer mode and welding metallurgy of stainless steel electrode

采用高速摄影、平板堆焊等试验方法,研究了典型金红石型不锈钢焊条熔滴过渡形态及其与焊接冶金学的相关性。结果表明,金红石型不锈钢焊条有渣壁过渡和混合过渡两种基本过渡形态,前者使焊条的综合工艺性极佳;后者随混合过渡中短路过渡成分的增加,焊条工艺性变差,常用的熔滴过渡形态评定方法有4种。两种熔滴过渡形态焊接冶金学特征差别在于:前者具有特大反应相界面等更有利条件,较后者冶金反应更激烈。熔滴过渡区的冶金反应对熔滴过渡形态的影响,很大程度受熔滴增Si量控制,熔滴增Si量较高时,熔滴的表面张力γD减小,熔滴易被细化,有利于形成渣壁过渡;反之,熔滴的γD较大,熔滴较粗,难于形成渣壁过渡。提出"熔滴过渡形态对气孔影响理论",凡是促使熔滴尺寸变化的因素,都将通过冶金原理对气孔产生影响,其影响规律与熔滴大小存在对应关系。

The correlation between the metal transfer mode and welding metallurgy of typical ruffle stainless steel electrode are studied by bead weld-on-plate weld and using the high-speed photography.The results show that there, are two basic metal transfer modes of typical futile covered electrode of stainless steel ,flux-wall guided transfer and mixed transfer.The general usability is best with flux-wall guided transfer and deteriorates as the increasing of proportion of short-circuiting transfer in the mixed transfer mode.There are four ways to assess the metal transfer mode in general.The difference of welding metallurgy between the two metal transfer modes is that the phase reaction interface in the flux-wall guided transfer is more than that in mixed transfer mode;therefore,the extent of metallurgical reaction in the flux-wall guided transfer is more drastic than that in mixed transfer.The effect of metallurgical reaction during droplet transferring on metal transfer mode is dominated by the addition of Si in the droplet to some degree.As the addition of Si in the droplet is higher, the surface tension of droplet is reduced ,the droplet is fined ,and therefore ,the transfer mode tends to be the flux-wall guided transfer. Whereas,as the surface tension of droplet is increased ,the droplet become coarse,it is difficult for droplet to transfer in flux-wall guided transfer mode.lt is the first time that ＂the theory of effect of metal transfer mode on gas cavity＂ is presented.The theory expounds that all factors which would influence the size of the droplet will affect the gas cavity,the influence rule corresponds to the size of droplet.