稀土金属对纯镍铸铁焊条抗热裂性影响的研究

Study on Influence of Rare Earth Metals on Hot Cracking Susceptibility of Pure Nickel Electrode for Welding of Cast Iron

采用HRL 1型热裂纹试验机测试焊缝临界变形速度的方法 ,研究了常用稀土金属镧、铈、镨、钇及钕在纯镍铸铁焊条冷焊时 ,对焊缝临界变形速度VBL、焊缝微观组织以及热裂敏感性的影响规律。试验结果表明 :焊缝中加入适量的稀土镧、铈、钇和镨 ,有脱硫、脱磷、去除晶界杂质的作用 ,每种稀土金属 ,偏离该最佳值都会使焊缝抗热裂性降低。纯镍铸铁焊条中加入稀土钕会增加焊缝热裂敏感性。稀土镧、铈、钇和镨能在一定范围内显著提高焊缝临界变形速度VBL,改善纯镍铸铁焊缝抗热裂性能。

Using the HRL 1 type hot cracking tester and the critical deformation velocity method, the principle and influence of La, Ce, Pr, Y and Nd on weld line critical deformation velocity V BL and microstructure and hot cracking susceptibility of the pure nickel electrode used for cold welding of cast iron was studied. Experiments show that there are uses of desulphurization, dephosphorus and removal impurities from the grain boundaries for the optimum value content of rare earth metal lanthanum, cerium, yttrium, praseodymium in weld metal and the deviate from this value led in a deterioration in hot cracking resistance properties. Neodymium can increase weld metal hot cracking susceptibility of the pure nickel electrode used for cold welding of cast iron. It is concluded that lanthanum, cerium, yttrium and praseodymium increase weld line critical deformation velocity V BL and improve the hot cracking resistance properties of the pure nickel electrode for welding cast iron to some extent.