论文部分内容阅读
对于D_6AC钢(σ_b=203.5kgf/mm~2)和24CrMnSiNi钢(σ_b=161.0kgf/mm~2),在裂纹张口处滴水的条件下进行了应力腐蚀开裂实验。在光学显微镜和干涉显微镜下观察并研究了应力腐蚀开裂所引起的试样表面形变现象。结果表明,表面形变对于不同强度级别的钢具有不同的特征。在试样表面上所观察到的应力腐蚀裂纹的开裂路径,大多沿着一侧形变带或两形变带的会合处。讨论了产生这种表面形变现象的机制,认为与观察到的应力腐蚀裂纹在试样厚度上呈舌形扩展有关,此时未开裂的薄的试样表面层在外力作用下经受剪切变形,因而造成所观察到的试样表面形变现象。
For D_6AC steel (σ_b = 203.5kgf / mm ~ 2) and 24CrMnSiNi steel (σ_b = 161.0kgf / mm ~ 2), stress corrosion cracking experiments were carried out under the condition of dripping water at the crack mouth. Under the light microscope and interference microscope, the surface deformation of the specimen caused by stress corrosion cracking was observed and studied. The results show that the surface deformation has different characteristics for different strength grades of steel. The cracking path of stress corrosion cracking observed on the specimen surface mostly follows the confluence of one or both deformation bands. The mechanism of this surface deformation is discussed. It is considered that the observed stress corrosion cracking is related to the tongue-like extension of the specimen thickness. At this time, the uncracked thin sample surface layer undergoes shear deformation under the external force, Thus causing the observed surface deformation of the sample.