Martensitic stainless steel powder exhibits a high nitrogen uptake when densified by supersolidus liquid-phase sintering in a nitrogen atmosphere, but the optimum uptake, which is beneficial to its resistance to corrosion, is unknown. In this study, the resistance of high-carbon martensitic stainless steel X190CrVMo20-4-1 densified in a nitrogen atmosphere against pitting corrosion was explored. This was to clarify the impact of nitrogen uptake in the steel matrix in the quenched and tempered condition on its corrosion resistance in an aqueous solution. Samples were subjected to potentiodynamic polarisation tests in a de-aerated, 1 wt% NaCl solution. Results revealed that the X190 steel densified in a nitrogen atmosphere at 40-kPa pressure, subjected to deep cryogenic treatment in liquid nitrogen at an austenitising temperature of 1150°C and tempered at 200°C, had the best pitting corrosion resistance with a breakdown potential of 142 ± 11 mV/SCE and a hardness of 738 ± 4 HV10. The matrix around the M₇C₃ carbides and MX carbonitrides suffered high pitting susceptibility. The implications of this study serve as a basis for the improvement of the functional properties of steels.

中文翻译：

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吸氮和热处理对超固相液相烧结X190CrVMo20-4-1钢显微组织特征和腐蚀性能的影响

马氏体不锈钢粉末在氮气氛中通过超固相线液相烧结致密化时表现出较高的氮吸收量，但有利于其耐腐蚀性的最佳吸收量尚不清楚。在这项研究中，研究了在氮气氛中致密的高碳马氏体不锈钢 X190CrVMo20-4-1 的抗点蚀性能。这是为了阐明在淬火和回火条件下钢基体中氮的吸收对其在水溶液中的耐腐蚀性的影响。在脱气的 1 wt% NaCl 溶液中对样品进行动电位极化测试。结果表明，X190 钢在 40-kPa 压力的氮气气氛中致密，经液氮深冷处理，奥氏体化温度1150℃，回火200℃，耐点蚀性能最好，击穿电位142±11mV/SCE，硬度738±4HV10。M 周围的矩阵₇ C ₃碳化物和MX碳氮化物具有高点蚀敏感性。这项研究的意义可作为改善钢的功能特性的基础。