摘要
研究了氮对含铬０．５％～１５％白口铁组织和性能的影响．试验结果表明，向铁水中增氮能改善碳化物形态与分布．在低铬白口铸铁中，加氮能促使其共晶碳化物断网；在高铬白口铸铁中，加氮能促进其共晶碳化物由长条状向团块状转变；在中铬白口铸铁中，加氮能促使其共晶碳化物由断网状分布向蠕虫状和团块状分布转化．且加氮还能强化铬白口铸铁基体，提高其冲击韧性和硬度，其韧性增幅最高可达５Ｊ／ｃｍ２以上．从加氮对铬白口铁的强韧化效果来看，以对中铬白口铁的强化效果最佳．
The effects of nitrogen on properties and structures of chromium white cast iron with 0.5%～15% cr were studied in this paper. It was showed in the experiment that reticulated eutectic carbides could be made broken away by adding some amount of nitrogen into a low chromium white cast iron, the shape of the eutectic carbides could be changed from needle like into granular blocked by adding some amount of nitrogen into a high chromium wihte cast iron, and the distribution of the eutectic carbides could be changed from reticulation broken into vermicular like or nodule like by adding some amount of nitrogen into a medium chromium white cast iron. Whatsmore,the addition of nitrogen into the alloy could strengthen the matrix organization and increase the impact toughness and hardness. And the maximum of its impact toughness values was increased by 5 J/cm 2. In a view of strengthening and toughening effects of nitrogen on chromium white cast irons,the effect of nitrogen on medium chromium white cast iron is the most satisfactory.
关键词
白口铁
组织
强韧化
nitrogen
chromium white cast iron
structures
properties
