氧含量对钢耐蚀性能的影响  

Effect of oxygen content on corrosion resistance of steel

作　　者：严春莲 秦汉成 崔桂彬 其其格 赵梦莹 刘锟 YAN Chunlian;QIN Hancheng;CUI Guibin;QI Qige;ZHAO Mengying;LIU Kun(Shougang Group Company limited Research Institute of Technology,Beijing 100043,China;Beijing Key Laboratory of Green Recyclable Steel Process,Beijing 100043,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]绿色可循环钢铁流程北京市重点实验室,北京100043

出　　处：《工程科学学报》2024年第4期704-714,共11页Chinese Journal of Engineering

摘　　要：为了考察氧含量对钢耐蚀性能的影响,冶炼了不同氧含量(质量分数在20×10-6~200×10-6范围)的碳钢和耐候钢.通过扫描电镜夹杂物分析、极化实验、全浸实验等方法研究了钢中夹杂物类型、形态、数量、尺寸等随氧含量变化而变化的规律,以及对耐蚀性能的影响.结果表明,随着钢中氧含量逐渐增大,钢中夹杂物由长条状MnS、Al2O3向颗粒状硅酸盐转变,夹杂物总数量、平均尺寸逐渐增大,譬如氧质量分数从20×10-6、60×10-6增大到195×10-6时,MnS数量占比从69.9%、23.7%减少到5.8%,硅酸盐数量占比从3.4%、54.9%增大到73.2%,夹杂物总面积分数从0.01%、0.04%增大至0.25%,等效圆直径从0.78µm、1.15µm增大至4.65µm;点蚀电位呈升高趋势,整体升高40 mV左右;腐蚀速率先下降又回升,遵从三次函数变化规律,其中氧质量分数从20×10-6~30×10-6增大到60×10-6,碳钢腐蚀速率降低53%,耐候钢腐蚀速率降低24%,耐蚀性均提高.分析认为,氧质量分数在20×10-6~100×10-6范围,易诱发腐蚀的长条状硫化物减少以及固溶氧增多而引起基体电位升高的共同作用导致在全浸腐蚀环境下钢的耐蚀性增强;氧质量分数在100×10-6~200×10-6范围,夹杂物的数量急剧增多使得钢的耐腐蚀性降低.适当增大氧含量,可开发经济型耐腐蚀钢.To explore the influence of oxygen content on the corrosion resistance of steels,carbon and weathering steels with different oxygen contents of(20×10-6–200×10-6)were smelted.Using scanning electron microscopy inclusion analysis,polarization curve test,and full immersion test,the change rules of inclusion type,shape,quantity,size,and corrosion resistance under different corrosion environments with changing oxygen content in steel were investigated.The findings indicated that with increasing oxygen content in the steel,the inclusions in the steel changed from long strip MnS and Al2O3 to granular silicate inclusions,and the total number and mean size of all inclusions increased gradually;for instance,with the oxygen content increasing from 20×10-6 to 60×10-6 and then to 195×10-6,the number fraction of MnS decreased from 69.9%to 23.7%and then to 5.8%,the number fraction of silicate increased from 3.4%to 54.9%and then to 73.2%,the total area fraction of inclusions increased from 0.01%to 0.04%and then to 0.25%,and the equivalent circle diameter(ECD)increased from 0.78µm to 1.15µm and then to 4.65µm,respectively.The pitting potential demonstrated a positive tendency,with an overall increase of about 40 mV.The full immersion corrosion rate first decreased and then increased,following the cubic function change rule.When the oxygen content increased from(20×10-6–30×10-6)to 60×10-6,the corrosion rate of carbon and weathering steel decreased by 53%and 24%,respectively.The corrosion resistances of carbon and weathering steels were enhanced,and the corrosion rate of weathering steel was evidently lower than that of carbon steel,which is below 3 mm·a-1.With the corrosion time prolonging from 24 h to 48 h and then to 96 h,the corrosion rates of carbon and weathering steels decreased significantly,and the corrosion gradually slowed down.From the analysis,there were mainly long strip sulfides in the steel with an oxygen content of(20×10-6–30×10-6).When the steel plate experienced pitting corrosion,the sulfides

关 键 词：氧含量 耐蚀性能 耐候钢 夹杂物 腐蚀速率 耐腐蚀钢 

分 类 号：TG174.2[金属学及工艺—金属表面处理]