新型奥氏体不锈钢焊接接头热腐蚀性能的研究

Investigation of Thermal Corrosion Resistance for New-Type Austenitic Stainless Steel Welded Joints

针对高参数、大容量电站锅炉对耐热材料的使用要求,采用新型奥氏体不锈钢SUPER304H、TP347H和HR3C,并基于锅炉管系工作环境,选用Na2SO4/NaCl作为热腐蚀介质,通过涂盐试样的热腐蚀性试验,研究焊接接头各区热腐蚀规律,利用SEM、XRD等分析手段观察腐蚀层形貌,分析腐蚀产物及成份.结果表明:在650℃,NaCl∶Na2SO4=2∶1的条件下,热影响区的耐热腐蚀性能最差,焊缝次之,母材的耐腐蚀性最好,腐蚀产物主要为Fe2O3、Cr2O3和NaFeO2.

Based on the requirements of heat resistant materials for large sized high parameter power station boilers,the austenitic stainless steel Susper304H,TP347HFG and HR3C are tested in Na2SO4/NaCl solution to study the thermal corrosion properties of the welded joints;XRD and SEM are used to analyze the morphology of and ingredients of the corrosion layer.When the corrosion temperature is 650℃ with Na2SO4∶NaCl=2∶1,the HAZ has the poorest corrosion resistance,followed the middle is weld,and the best is base metal with the corrosion products of Fe2O3,Cr2O3 and NaFeO3.