V90r5M02高速钢中碳化物三维形态研究

通过对试样进行深度腐蚀，利用扫描电镜研究不同碳含量的V9Cr5M02高速钢中碳化物的三维形貌，并进一步讨论了碳化物的形态与舍金凝固结晶过程的关系。结果表明，V9Cr5M02高速钢中碳化物主要由VC及以铬、钼为主的复合碳化物组成；共晶VC为枝晶状，先析出VC为不规则块状、开花状、卵石堆积状及团球状；以铬为主的复合碳化物为曲面板条状；富钼复合碳化物为鱼骨状。合金中含碳量1．6％时，碳化钒主要为共晶VC；碳含量为2．5％时，VC主要为大量共晶VC及部分不规则团块状、开花状的初生VC；碳含量为3．2％及4．2％时，VC为大量初生VC。随着含碳量的增加，VC的形态也由卵石堆积状向分散分布的团球状转变。

Study of the Three-dimensional Morphology of Carbide in VgCrSMo2 High Speed Steel

The three-dimensional morphology of carbide in V9Cr5Mo2 high speed steel with different carbon content were studied by scanning electron microscope after the samples are excessively corroded, and the relationship between the shapes of carbide and the solidification are discussed further. The result indicates that the carbides in V9Cr5Mo2 high speed steel are mainly composed of VC and compound carbide with a majority of chromium and molybdenum; Eutectic VC is dendritic crystal, the prime VC has irregular block, floral shape, pebble stack and nodular shape; The compound carbide with major chromium has lath-shape with curved face and bacillary and the compound carbide with major molybdenum has herringbone-like shape. When carbon is 1.6wt%, eutectic VC is mainly existed; when carbon is 2.5wt%, prime VC exists mainly as eutectic VC and partial irregular block, and floral shape; VC is a great deal of prime precipitation when carbon is 3.2wt% and 4.2wt%, the morphology of VC change from pebble stack to nodular shape.