Cu-P耐候钢中稀土对夹杂物和耐蚀性的影响

通过金相光学显微镜、JSM 6400扫描电镜及能谱仪对洁净度较好的两组试验耐候钢板坯进行分析观察,采用非水电解分离夹杂和ICP方法分析钢中固溶稀土含量·采用干 湿周浸室内加速试验方法对试验钢和对比A3钢进行了研究,测得了试验钢的腐蚀率·并用电化学方法测得了带锈样的极化曲线·研究得出试验稀土耐候钢中全氧在～0 002%,硫在～0 004%的水平时,稀土总含量为0 0065%～0 016%,可以保证长条硫化物基本变质,且随着稀土含量的增加钢的耐腐蚀性能逐步提高·全氧在0 002%～0 007%,硫在～0 008%的水平时,稀土总含量为0 005%～0 025%,可以保证长条硫化物基本变质·

Cu-P Weather Resistance Steel:Influence of Rare Earths on Nonmetallic Inclusions and Anticorrosivity

Two groups of the RE weathering resistant steel slabs were observed and analyzed for testing with metalloscope and SEM/EMPA. Solid-soluble content of rare earths in steel was analyzed by nonaqueous electroanalysis and ICP. The weathering resistance of the steel and steel Q235 as reference specimen were studied by dry-wet immersion test, with their corrosion rates obtained. The polarization curves of the RE steel and Q235 were measured by electrochemical methods. A conclusion was drawn that when the content of oxygen/sulfur of the steel specimens is about 0.002%/0.004% the optimum content of RE is 0.0065%-0.016%, thus causing the bar-like sulphides to nearly deteriorate and improving gradually the anticorrosity of the steel with the increase of RE content. When the content of oxygen/sulfur is about 0.002%-0.007%/0.004%, the optimum content of RE is 0.005%-0.025%, with near-deterioration of bar-like sulphides observed.