(上海材料研究所,上海 200437)
摘要:940X不锈轴承钢是由上海材料研究所开发的具有高硬度、耐海水腐蚀的一种新型不锈轴承钢。940X不锈轴承钢经热处理后,室温硬度HRC 56~58;屈服1410MPa, 抗拉1820MPa。在450℃和500℃高温时,显微硬度HV5分别为504和471,相应的洛氏硬度HRC分别为49.5和47.2 , 940X不锈轴承钢在高温条件下也具有高的硬度。在模拟海水的NaCl溶液中的腐蚀试验表明,940X不锈轴承钢具有良好的耐海水腐蚀的能力。在35℃的5%NaCl溶液进行盐雾试验,940X不锈轴承钢加工的轴承,经120h盐雾试验后无锈蚀;而对比材料9Cr18加工的轴承24h盐雾试验出现锈蚀。30℃的3.5%NaCl溶液中940X不锈轴承钢点蚀电位+30mV/SCE,远高于9Cr18不锈轴承钢-230 mV/SCE。并结合化学成分及金相能谱分析研究了940X不锈轴承钢的高硬度、耐海水腐蚀机理。
关键词:940X不锈轴承钢,耐海水腐蚀、高硬度
中图分类号:TG174.2 文献标识码:A DOI:10.6052/0459-1879-12-345
Huang Chun-bo, Xue-Chun, Shen Zhong-liang
(Shanghai Research Institute of Materials, Shanghai 200437, China)
Abstract: A new stainless bearing steel 940X with high hardness and good corrosion resistance of seawater, is developed by Shanghai Research Institute of Materials. Stainless steel 940X had high hardness of 56~58 HRC, high yield strength of 1410 MPa and tensile strength of 1820 MPa at room temperature. The hardness of Steel 940X at 450℃ and 500℃ was 49.5 HRC and 47.1 HRC, which related to high temperature vickers microhardness 504 HV and 407 HV, respectively. So Steel 940X had high hardness at high temperatures. Results of corrosion tests in NaCl solutions showed that Steel 940X had good corrosion resistance of seawater. Results of spraying salt test in 5% NaCl solution at 35℃ showed that surface of steel 940X was not corroded after testing for 120 hours while surface of steel 9Cr18 was corroded after testing for 24 hours only. The pitting potential of Steel 940X was +30mV/SCE which being higher much than that -230 mV/SCE of Steel 9Cr18 in 3.5% NaCl solution at 30℃. Mechanism of high hardness and good corrosion resistance of seawater of Steel 940X was investigated by means of chemical composition, micrograph and EDS.
Key Words: Stainless bearing Steel 940X, good corrosion resistance of seawater, high hardness.