一、绪论众所周知,机械产品质量的可靠性和寿命,已经不仅仅只限于保证尺寸、金相组织等而能奏效;而更有其内在的因素,例如应力测量务必加以考虑。内应力,特别是拉应力的存在,会导致裂纹的扩展和断裂。内应力还能引起金属材料内部氢化物沿晶界析出而脆裂。例如,加拿大皮克林重水反应堆锆管接头胀接内应力集中,导致氢化锆 I. INTRODUCTION As we all know, the reliability and life expectancy of mechanical product quality have not only been validated by ensuring the size, microstructure and so on, but also its inherent factors such as stress measurement must be taken into account. Internal stress, especially the presence of tensile stress, can lead to crack propagation and fracture. Internal stress can also cause the internal hydride metal material precipitation along the grain boundary and brittle fracture. For example, Canadian Pickering heavy water reactor zirconium pipe joint expansion stress concentration, resulting in zirconium hydride