Abstract

The effect of silicon (in range 0.14–0.78 wt %), boron, and rare-earth metals (REM) on the corrosion resistance of low-carbon austenitic chromium-nickel steel of 03Kh18N11 (AISI 304L) grade was studied. It is shown that all steels in the quenched state when tested in boiling 56 and 65% HNO₃ solutions have comparable corrosion rates, which do not exceed the critical norm (0.5 mm/year) in accordance with GOST 6032–2017 (State Standard). Testing samples in boiling 27% HNO₃ + 4 g/L Cr⁺⁶ solution are susceptible to intergranular corrosion (IGC). The corrosion rate and the penetration depth of IGC increase with additional silicon concentration from 0.14 to 0.78 wt %. The study focused on the effect of nitric acid concentration and test temperature has shown that steel with 0.78 wt % Si has significant corrosion losses exceeding the critical ones when testing in 56 and 65% HNO₃ solutions with temperature of 120 and 130°С. But steel with high silicon content (0.78 wt %) and low carbon concentration (0.020–0.022%) after quenching in a range of 1080–1150°C and tempering at 650°C does not exceed the critical norm on average corrosion rate. Only 0.01 wt % increase in carbon concentration leads to a significant (more than 30 times) increase in corrosion rate of sensitized steel. It is shown that microalloying with REM does not impair corrosion resistance of sensitized steel. In contrast to REM, alloying chromium-nickel steel with even a small addition of boron (0.0015%) reduces steel corrosion resistance by an order of magnitude. Corrosion rate inverse dependence on quenching temperature is observed when, with increasing temperature, corrosion rate of 02Kh18N11GS0.38R steel increases.

中文翻译：

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硅，硼和稀土金属对奥氏体铬镍钢耐蚀性的影响

摘要

研究了硅（含量在0.14-0.78 wt％范围内），硼和稀土金属（REM）对03Kh18N11（AISI 304L）级低碳奥氏体铬镍钢耐蚀性的影响。结果表明，在沸腾的56和65％HNO ₃溶液中测试时，所有处于淬火状态的钢都具有可比的腐蚀速率，根据GOST 6032–2017（国家标准），其腐蚀速率不超过临界标准（0.5毫米/年）。 。在沸腾的27％HNO ₃ + 4 g / L Cr ^+6中测试样品溶液易受晶间腐蚀（IGC）的影响。随着额外的硅浓度从0.14wt％到0.78wt％，IGC的腐蚀速率和渗透深度增加。针对硝酸浓度和测试温度的影响的研究表明，当在56和65％HNO _3中进行测试时，含0.78 wt％Si的钢的腐蚀损失超过了临界腐蚀损失。温度为120和130°С的溶液。但是，在1080–1150°C的温度范围内淬火并在650°C的温度回火后，硅含量高（0.78 wt％）和碳含量低（0.020–0.022％）的钢没有超过平均腐蚀速率的关键指标。碳浓度仅增加0.01 wt％会导致敏化钢的腐蚀速率显着提高（超过30倍）。结果表明，与REM进行微合金化不会损害敏化钢的耐腐蚀性。与REM相比，即使仅少量添加硼（0.0015％）的合金化铬镍钢也会使钢的耐腐蚀性降低一个数量级。当02Kh18N11GS0.38R钢的腐蚀速率随温度升高而升高时，腐蚀速率与淬火温度成反比。