纳米大理石对D600R堆焊焊条性能的影响

用粒径70～90nm大理石取代堆焊焊条D600R药皮中的微米大理石,制成纳米大理石焊条.利用汉诺威电弧质量分析仪对焊接过程中的电流电压和短路时间进行测试,获得微米大理石焊条和纳米大理石焊条的燃弧特征;通过焊接工艺试验、测氢试验、熔化温度测试、硬度试验、耐磨试验和微观分析,分别对两种焊条的工艺性能和力学性能进行分析.结果表明,用纳米大理石替代微米大理石可降低焊条药皮的熔化温度和堆焊层金属中的扩散氢含量;提高焊条的熔敷效率;降低焊条短路电压、短路电流概率密度和,在短路时间t12.05ms时间段内缩短累计短路时间;改善焊条操作性能;提高堆焊层金属硬度和耐磨性.

Influence of nano-scale marble on properties of D600R surfacing electrode

The nano-scale marble electrode was made,which conventional micron-scale marble in the coating of D600R,a hardfacing shielded metal-arc welding electrode,was replaced by nano-scale marble (CaCO₃) with particles size ranges of 70-90 nm. The welding current,arc voltage and short-circuiting time were measured with an arc characteristics analyzer (Hannover analystor),and the arc characteristics of the micron-scale marble and nano-scale marble electrodes were obtained. By means of welding procedure test,hydrogen test,melting temperature and hardness measuring,wear test and micro-analysis,the welding processing properties and mechanical properties of deposited metal of the two electrodes were studied respectively. The results show that when micron-scale marble is replaced by nano-scale marble,the melting temperature of coating and the amount of diffusible hydrogen in deposited metal are decreased,and the deposition efficiency of electrode is increased; the probability density sum of short-circuiting voltage and short-circuiting current,and the sum of short-circuiting time,including over 2.05 ms,are all decreased,and the electrode operating properties are improved; the hardness and wear resistance of deposit metal are enhanced.