论文部分内容阅读
利用光学显微镜和扫描电子显微镜,通过高温持久试验分析了700℃试验中HR3C钢焊接接头蠕变组织。结果表明,高温持久拉伸的HR3C钢接头组织中析出大量粗大的M23C6沿奥氏体晶界连续分布是促使蠕变裂纹产生的原因;在焊缝胞状树枝晶内的M23C6以针状形态几乎布满整个组织,加速了裂纹扩展,致使接头的蠕变断裂强度降低。
The creep microstructure of HR3C steel welded joints in 700 ℃ test was analyzed by means of optical microscope and scanning electron microscope. The results show that the continuous distribution of large amounts of coarse M23C6 along the austenite grain boundaries in HR3C steel joints with high temperature lasting elongation is the reason that causes the creep cracks to occur. In the weld cell dendrites, M23C6 is almost cloth Filled the entire organization, accelerated crack propagation, resulting in reduced strength of the joint creep rupture.