【摘要】 3块Zr-4板经过800℃真空热轧扩散焊接的样品,在400℃过热蒸汽中腐蚀150天后会发生重新开裂,用光学显微镜观察样品截面上显微组织的变化;用微区成分分析方法研究了焊接面处与基体成分之间的差别。结果表明:焊接面上C元素的污染引起焊接面耐腐蚀性能的变坏,以及氧化-氢化联合作用导致了焊接面的开裂。更多还原

【Abstract】 The welding joints of three plates of Zircaloy-4 obtained by hot rolling diffusion welding at 800℃ in vacuum were cracked during autoclave tests at 400℃ superheated steam after exposure longer than 150 days.The section of specimens was examined by optical microscopy and the composition of mi-cro-area at the welding seams and the matrix was analyzed and compared.The result shows that the con-tamination of carbon at the welding surface and the combination of oxidation and hydriding induced cracking is responsible for the cracking of welding seams during autoclave testing.更多还原