Cr-Ni-Cu系Ⅰa钢级低合金耐候钢管耐蚀性能研究

Study on Corrosion Resistance of Weathering Steel Tube Made of Cr-Ni-Cu Series Grade Ⅰa Low Alloy Steel

对性能相近的Cr-Ni-Cu系Ⅰa钢、Q345B和X52Q钢进行盐雾试验,通过观察腐蚀面变化情况,对比试验前后称重情况,分析耐候钢Ⅰa钢级的抗腐蚀性能。试验结果表明:各钢种在48,120,168 h腐蚀情况无明显差别,但除锈后Ⅰa锈层较Q345B和X52Q略致密;短时间内抗盐雾腐蚀性X52Q∧Ⅰa∧Q345B,与通过耐大气腐蚀指数不同,这可能是受试验时间、晶粒尺寸、合金元素和显微组织的影响。

Salt spray tests are performed on 3 steel types with silimar properties, i.e., Cr-Ni-Cu series grade I a steel, Q345B steel and X52Q steel. The corrosion resistance of grade I a weathering steel is then analyzed by observing the changing of the corroded surfaces and comparing the differences between the weights before and after the tests. The tests show the following results. The corrosions of different steel types at 48, 120 and 168 hours have no significant difference, but the rust layer of grade I a steel presented after descaling is a little more compact than that of Q345B steel and X52Q steel. The resistances of these types of steels against salt-spray corrosion in short time periods show that X52Q〉 Ia〉Q345B, different from the values calculated using atmospheric corrosion resistance indexes, which might be the result of the influence of testing time, grain size, alloy elements and microstructure.