论文部分内容阅读
测定了18-5-Nb双相(α-γ)不锈镉U形弯曲SCC试样中的形变马氏体量与预拉伸塑性形变量的关系;研究了室温拉伸塑性形变对18-5-Nb钢耐氯化物应力腐蚀(SCC)性能的影响,试验介质为25％NaCl+1K_2Cr_2O_7％沸腾溶液。试验结果指出,拉伸塑性形变可诱导钢中的γ相发生马氏体相变,形变马氏体量随形变量的增加而增加。室温拉伸塑性形变寻致18-5-Nb钢的耐氯化物SCC性能明显恶化。试验表明,拉伸塑性形变后的18-5-Nb钢在NaCl溶液中的SCC以点蚀为起源;在SCC裂纹的产生和扩展过程中,γ相的选择性腐蚀起着重要作用。
The relationship between the amount of deformed martensite and the amount of pre-tensioned plastic deformation in U-bend SCC specimens of 18-5-Nb duplex stainless steel (α-γ) was measured. The effects of room temperature tensile plastic deformation on the tensile properties of 18- 5-Nb steel resistance to chloride stress corrosion (SCC), the test medium is 25% NaCl + 1K_2Cr_2O_7% boiling solution. The experimental results show that the tensile plastic deformation can induce martensitic transformation of γ phase in steel, and the amount of deformed martensite increases with the increase of deformation. Tensile plastic deformation at room temperature induced 18-5-Nb steel chloride resistance of SCC significantly deteriorated. Experiments show that the SCC of 18-5-Nb steel in NaCl solution is pitting-induced. The selective corrosion of γ phase plays an important role in the SCC crack growth and propagation.