N800CF低碳贝氏体钢及其焊接接头腐蚀行为研究

Study on corrosion behaviors of N800CF low carbon bainitic steel and its welded joint

采用周期浸蚀试验研究了N800CF低碳贝氏体钢及其焊接接头在模拟工业大气环境下的耐腐蚀行为,并与SMA490BW和Q345C两种材料进行了对比。通过计算腐蚀失重率以及电化学极化曲线分析其腐蚀行为与机理。结果表明,N800CF低碳贝氏体钢耐工业大气腐蚀性能低于SMA490BW耐候钢,但好于Q345C低合金钢;N800CF低碳贝氏体钢接头的耐蚀性能高于母材,且不同焊接热输入下的N800CF低碳贝氏体钢接头在腐蚀前期耐蚀性相差不大,随着腐蚀时间的延长,线能量为15 kJ/cm时焊接接头耐蚀性最好,当线能量达到18 kJ/cm时其耐蚀性相对较差。

The corrosion resistance behaviors of N800CF low carbon bainitic steel and its welded joint were investigated in simulated industrial atmosphere by means of alternate imm-ersion tests.Comparative analysis between SMA490BW and Q345C was conducted.The corrosion behaviors and mechanisms were studied by corrosion weight loss rate and electrochemical polarization curves.The results show that the corrosion resis-tance of N800CF is worse than that of SMA490BW but better than that of Q345C under simulated industrial atmosphere condition.The N800CF welded joint has better corrosion resistance than that of the base material.The welded joints with different heat inputs have similar corrosion resistance in the prior corrosion period.The welded joints with 15 kJ/cm heat input have the best corrosion resistance,and become worse when heat input reaches 18 kJ/cm.