加热气氛对一种C-Mn-Si-Al高强钢选择性氧化的影响

Effects of heating atmosphere on selective oxidation of a C-Mn-Si-Al high strength steel

为了研究局部露点技术在含铝高强钢上应用的潜力,采用热浸镀工艺模拟器研究了加热过程的露点温度对一种C-Mn-Si-Al高强钢选择性氧化的影响。加热过程中的露点温度设置为-10、-20和-50℃,而在保温过程中的露点温度为-50℃。采用SEM/EDS表征了退火后试样表面的氧化形貌和元素质量分数,使用GDOES分析了退火试样表层的元素深度分布,采用XPS分析鉴定了试样表面的氧化物种类。试验结果表明,使用-10℃露点温度加热时,试样表面氧化轻微,铝元素出现明显内氧化现象。随着加热过程露点温度降低到-50℃,试样表面出现较多富含锰和铝的氧化物。因此,加热过程中较高的露点温度可以抑制合金元素向外表面的富集,减少试样表面的氧化物数量。

To research potential of applying local dew point technology on Al-bearing high strength steel,effects of dew points during heating on selective oxidation behavior of a C-Mn-Si-Al steel were studied through a hot-dip process simulator（HDPS）. The dew points during heating were set as-10,-20 and-50 ℃,respectively,while the dew point during soaking was-50 ℃. External surface of as-annealed steel samples was characterized by SEM/EDS. Alloying element profiles were detected by GDOES. Kinds of compound on the external surface were identified by XPS. As heating with the dew point of-10 ℃,little oxides could be found on the external surface and remarkable internal oxidation of Al could be found. As the dew point during heating decreased to-50 ℃,much more oxides composed with manganese and aluminum were observed on the external surface. Therefore,high dew point during heating extremely suppress enrichment of alloying elements and formation of oxides on the external surface for the C-Mn-Si-Al steel.