超低碳低铬镍高硅铸造不锈钢组织及点蚀行为

Microstructure and pitting corrosion behavior of super low carbon low chromium-nickel high silicon cast stainless steel

采用金相显微镜、X射线衍射、电子探针、扫描电镜和扫描隧道显微镜，研究了新型超低碳低铬镍高硅铸造不锈钢的组织及点蚀行为，并与性能优良的C15钢作了对比试验。试验分析结果表明，新型钢经1050℃水冷固溶处理后，可得到在铁素作基体上分布有适量奥民体的双相组织，组织明显细化与均匀化，具有比C15钢更好的抗点蚀性能。通过扫描隧道显微镜观测，得到了新型钢的超高分辨三维点蚀形貌图象，为新型钢的开发应用奠定了技术基础。

Metallographic AncroscoPe, x-ray diffraction spectrum, electronic probe, scanning electron microscope(SEM) andscanning tunneling microsecope(STM) are used to investigate microstructure and pitting corrosion behaviour of new superfow carbon fow chromium-nickel high silicon cast stainless steel. Conntraet test of the new steel and C15 steel is conduct-ed. Test and analysis results show that, the new steel has duplex strueture with proper amount of austenite dispersinginferrite matrix and better pitting corrosion resistance than that of C15 steel after solution heat treatment at 1050℃. Bymeans of STM, 3-D pitting images with ultra-high resolution can be obtained. And these biasic work is helpful to the ap-plication of the new steel.