Handoko Wilson, Pahlevani Farshid, Sahajwalla Veena
Centre for Sustainable Materials Research and Technology (SMaRT Centre), School of Materials Science and Engineering, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia.
Materials (Basel). 2018 Nov 28;11(12):2404. doi: 10.3390/ma11122404.
Steel has played a primary role as structural and fabricating materials in various industrial applications-including the construction sector. One of the most important properties of steel that required a constant improvement is corrosion resistance specifically in corrosive environment. For this purpose, various approaches have been conducted through different heat treatment parameters to compare its microstructural engineering on chemical and mechanical properties. In this paper, correlation of different microstructure on corrosion resistance and hardness properties have been investigated. Three different heat treatment cycle have been applied on carbon steel with same composition to prepare dual-structure (DS) steel that consisted of ferrite/pearlite and triple-structure (TS) with ferrite/pearlite/bainite and ferrite/bainite/martensite. Phase transformation during heat treatment process was analyzed through in-situ ultra-high temperature confocal microscopy. Effect of corrosion behavior on these steels was investigated by Tafel plot, Scanning Electron Microscopy (SEM), 3D laser scanning confocal microscopy (3DLSCM), and calculation of phase volume fraction by ImageJ. Mechanical test was conducted by Vickers hardness test. It has been found that TS steels that have improvement in corrosion resistance accounted around 5.31% and hardness value for up to 27.34% more than DS steel, because of tertiary phase-bainite/martensite. This corrosion rate was reduced due to decreased numbers of pit growth and lower level of boundary corrosion as bainite/martensite phases emerged.
在包括建筑行业在内的各种工业应用中，钢材一直是主要的结构和制造材料。钢材最重要的性能之一是耐腐蚀性，特别是在腐蚀性环境中，这需要不断改进。为此，通过不同的热处理参数采用了各种方法，以比较其在化学和机械性能方面的微观结构工程。本文研究了不同微观结构与耐腐蚀性和硬度性能之间的相关性。对具有相同成分的碳钢应用了三种不同的热处理循环，以制备由铁素体/珠光体组成的双相钢（DS）以及由铁素体/珠光体/贝氏体和铁素体/贝氏体/马氏体组成的三相钢（TS）。通过原位超高温共聚焦显微镜分析了热处理过程中的相变。通过塔菲尔曲线、扫描电子显微镜（SEM）、三维激光扫描共聚焦显微镜（3DLSCM）以及使用ImageJ计算相体积分数，研究了这些钢的腐蚀行为影响。通过维氏硬度测试进行力学测试。结果发现，由于第三相贝氏体/马氏体的存在，三相钢的耐腐蚀性提高了约5.31%，硬度值比双相钢高出27.34%。随着贝氏体/马氏体相的出现，点蚀生长数量减少和边界腐蚀程度降低，腐蚀速率降低。
