【摘要】 本文采用钨极氩弧熔融来模拟焊缝,研究在CaF₂保护下C-Mn-Si系焊缝金属中,影响针状铁素体形成的因素。结果表明,当Si、Mn比在一定的范围时,焊缝中将出现高比例的针状铁素体;且在大尺寸奥氏体晶粒中的非金属夹杂物上形核,高密度微小的夹杂物（1μm以下）的弥散分布对其形核更为有利。如果在以上的合金系统中加入T_i,能显著提高形成针状铁素体的机率。更多还原

【Abstract】 In this paper, an investigation on the factors affecting the formation of acicular ferrite in C-Mn-Si weld metals under the shield of CaF₂ with simulated weld metal melted by TIG arc was described. The results indicated that a high volumetric ratio of acicular ferrite in the simulated weld metal can be obtained in case the ratio of manganese and silicon is in a certain range. The nucleating centers are the non-metallic inclusions in the larger bainite grains. A high volume fraction of dispersive inclusions of small size （generally less than 1μm） in the weld metal is good for the formation of acicular ferrite. Micro-quantity of Ti in the weld metal may increase the probability of acicular ferrite formation.更多还原