碱度对直流埋弧焊熔滴阶段电化学致氧的影响

Effect of basicity index on electrochemically induced oxygen content at droplet reaction stage in direct current submerged arc welding

关键词:  碱度  电化学反应  埋弧焊

Key words:  basicity index  electrochemical reaction  submerged arc welding

摘要:

采用试验室设计各种碱度烧结焊剂在两种极性条件下进行快速焊接提取激冷态熔滴金属,应用LECO氧氮分析仪测定其氧氮含量,以间接分析焊接电弧阴极和阳极熔渣/液态金属界面发生的冶金电化学作用。结果表明,在焊丝末端熔滴生长阶段,直流反极性条件下存在电化学增氧,而直流正极性条件下则存在电化学脱氧。试验揭示出碱度对这种冶金电化学作用有着极为重要的影响,随着碱度的增大,受熔渣离子特性电极反应动力学的影响,其产生的与热化学活性理论相反的电化学致氧效应愈加明显,从而成为有必要加以考虑的冶金因素。

Abstract:

Agglomerated fluxes with different basicity index were used in high-speed welding so as to attain rapid cooled droplet metal under two polarity conditions.The oxygen content of droplet metal was measured using oxygen-nitrogen instrument in order to analyze indirectly metallurgy electrochemical reaction occurred at interface between molten slag and liquid metal in cathode and anode of welding arc.The result showed that it is in the period of droplet growth at the tip of welding wire that an electrochemically gained oxygen was produced in the case of direct current negative polarity whereas an electrochemically lost oxygen in positive polarity.The slag basicity index has great influence upon metallurgy electrochemical reaction.With slag basicity index increasing,the effect of electrochemically induced oxygen which is contrary to thermochemical reaction become more evident for reacting dynamics dependeding on its ion characteristic and therefore it is necessary to be considered as an metallurgy factor.