蠕墨铸铁同质焊缝冷裂纹启裂与扩展研究

Study of cold crack initiation and propagation of compacted graphite iron weld

蠕墨铸铁同质焊缝的焊接接头试件经抛光后,在拉力试验机上装机,经不同载荷试验后取下试件,考察了蠕墨铸铁焊缝冷裂纹的启裂与扩展过程。裂纹易在邻近石墨之间的窄的金属桥发生,也易从石墨尖端发生。裂纹的进一步扩展是沿着连接石墨数最多的通道发展。

The specimens cf welded joint of compacted graphite cast iron with homogeneous electrode were polished and then stressed under diffrent load on a tensile testing machine. Then the specimens were taken down to examine the crack initiation and propagation of the compacted graphite iron weld. Results showed that cracks were liable to be initiated in the narrow metal bridge between close graphites as well as from the tip of graphite. Further propagation cf crack developed along a path connecting the highest number of graphites.