Compositional characterization of inclusion/matrix boundaries and relation to pit initiation at MnS in stainless steel
Compositional characterization of inclusion/matrix boundaries and relation to pit initiation at MnS in stainless steel
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DOI：
10.1149/05838.0039ecst
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
Masayuki Tohjoh;I. Muto;A. Chiba;Y. Sugawara;N. Hara
中科院分区：
文献类型：
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作者：
Masayuki Tohjoh;I. Muto;A. Chiba;Y. Sugawara;N. Hara
用微电化学方法研究了不锈钢中MnS夹杂物/基体界面的组成特征及其与点蚀萌生的关系。在0.1M NaCl溶液中，含N的304 L不锈钢（0.12质量% N），没有发生MnS溶解。薄膜层被发现在MnS/钢的边界。Cr和C在薄膜层中积累。Cr的过钝化溶解电位比MnS的溶解电位正。由于MnS被薄膜层覆盖，因此认为MnS不溶解。MnS夹杂具有Cr的固溶性，在凝固过程中形成（Mn，Cr）S夹杂。认为在热处理过程中，Cr从（Mn，Cr）S向钢基体扩散，形成薄膜层。关于C，由于极化前夹杂物中几乎没有C的信号，因此认为C在腐蚀过程中积累在薄膜层中。
Compositional characterization of inclusion/matrix boundaries and relation to pit initiation at MnS in stainless steel were investigated by microelectrochemical measurements. In 0.1 M NaCl solution, N-containing 304L stainless steel (0.12 mass% N), MnS dissolution did not occurred. The thin-film layer was found at MnS/steel boundaries. Cr and C accumulated in the thin-film layer. The transpassive dissolution potential of Cr is considered to be more positive than dissolution potential of MnS. Since MnS was covered with the thin-film layer, it is thought that MnS did not dissolve. MnS inclusions have the solubility of Cr, so that (Mn, Cr) S was formed in the solidification process. It is thought that when Cr diffuse from (Mn, Cr) S to steel matrix during heattreatments, the thin-film layer is formed. About C, since there is almost no signal of C in inclusions before polarization, C is considered to be accumulated in the thin-film layer during the corrosion.