【摘要】 采用快速水冷和空冷两种不同的轧后冷却制度得到强度范围在490~980MPa级的低碳微合金结构钢。用户外间断喷淋3.5%NaCl水溶液来模拟海洋大气腐蚀,对带锈试样进行电化学阻抗谱测试,并对锈层中腐蚀产物进行了观察分析。结果表明,不同强度级别的低碳微合金钢的长期耐腐蚀性能相近,并略优于商业化耐候钢09CuPCrNi。提高钢基体的组织均匀性有利于改善钢的初期腐蚀性能,在形成保护性锈层之前,基体腐蚀深度较小。少量颗粒细小相的存在。有利于提高钢基体与锈层的结合力;但大块珠光体的存在会危害钢的初期腐蚀性能,因此耐候钢09CuPCrNi初期腐蚀速率较大。更多还原

【Abstract】 The microalloyed steel(LCS) with strength ranged in 490～980MPa was prepared by vacuum arc melting and water cooling or air cooling after finishing rolling,respectively.Corrosion behaviors of LCS were studied using accelerated outdoor test by intermittent spraying of a NaCl aqueous solution(3.5 wt%) and compared with traditional weathering steel(WS) 09CuPCrNi.Electrochemistry impedance spectra of the specimens were measured and rust phases were analyzed.The results indicate that corrosion resistance of the low carbon microalloyed steels with obviously different strength is almost same and lightly superior to that of 09CuPCrNi steel.Initial corrosion behavior can be improved by increasing the uniformity of the microstructure,which results in the small corrosion depth before the protective rust layer come into being.Small amount of the second fine phases in steel is profitable to improve the binding force between steel matrix and rust layers,whereas,coarse pearlite harms the initial corrosion resistance,accordingly,the initial corrosion rate of 09CuPCrNi steel is higher than that of the low carbon microalloyed steels.更多还原