热处理温度对510L热轧带钢原始氧化皮结构及其腐蚀行为的影响

Effects of Heat Treatment Temperature on Structure and Corrosion Behavior of Original Oxide Scale on 510L Hot Rolled Strip

利用不同温度的热处理工艺改善510L热轧带钢表面原始氧化皮结构,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、EDS、电化学测试方法对不同结构氧化皮的热轧带钢在NaHSO3溶液中的腐蚀行为进行了研究。结果表明:当温度低于570℃时,随氧化温度的增加,氧化皮上分布的白色弥散状组织减少,氧化皮的微观形貌由带毛刺的小颗粒状演变成针叶状,氧化皮更致密,氧化皮中的Fe2O3的相对含量增加。不同温度制备的热轧带钢氧化皮的耐蚀性由好到差依次为550,500,450,400,350℃。氧化温度介于570℃>T>450℃时,原始氧化皮的耐蚀性可通过热处理得到改善。

The structure of surface original scale of 510L hot rolled strip was processed by heat treatment at different temperatures.Corrosion behavior of hot rolled strips with different oxide scales structure was investigated in sodium bisulfite solution by SEM,XRD,EDS,polarization curves and electrochemical impedance spectroscopy（EIS）.The results show that when temperature is below 570℃,the microstructure of oxide scale evolved into coniferous shape from granular with burr,the oxide scales become more dense and the relative content of Fe2O3 increases with temperature increasing.White diffusion-like phases on the oxide scales reduce with temperature adding,while the thickness of oxide scales increases.The order of corrosion resistance of the scales prepared at different temperatures from good to poor is as follows： 550,500,450,400,350℃.When 570℃T 450℃,the corrosion resistance of original scale can be improved by heat treatment.