06Cr25Ni20氧化铁皮演变及机制探讨

Evolution and mechanism analysis of oxide scale of 06Cr25Ni20 stainless steel

工业生产的06Cr25Ni20钢卷经过不同温度、不同时间氧化,通过SEM、XRD检测分析发现:在800~900℃/20 h下,生成Cr2O3和MnCr2O4氧化层,随着氧化时间延长,在120 h时形成最外面为MnCr2O4尖晶石结构,中间为Cr2O3,最里面为SiO2的3层氧化皮结构,在140 h时,氧化层中间层大量Cr2O3生成MnCr2O4,氧化层中的MnCr2O4尺寸略有增加;温度和时间对06Cr25Ni20抗氧化性影响显著,在800℃氧化时,随时间的延长样品氧化速率变化很小,而当温度升高到1 000℃时,样品其氧化速度迅速升高,在100 h前其速率呈直线下降,100 h后氧化速率趋于平缓,减小程度变小。现场结合氧化铁皮生成结构和氧化速率规律进行酸洗工艺调整,钢卷表面质量和生产效率得到极大的提高。

The 06 Cr25 Ni20 steel coil was oxidized at different temperatures and time, SEM and XRD analysis showed that Cr2O3 and MnCr2O4 oxide layers were formed at 800-900 ℃/20 h. With the increase of oxidation time, three-layer oxide scale structures with MnCr2O4 spinel structure at the outermost layer, Cr2O3 in the middle layer and SiO2 in the innermost layer were formed at 120 h. At 140 h, a large amount of Cr2O3 in the middle layer of oxide scale generates MnCr2O4, and the size of MnCr2O4 in the oxide layer increased slightly. The oxidation resistance of 06 Cr25 Ni20 was significantly affected by temperature and time. The oxidation rate of 06 Cr25 Ni20 changed little with time at 800 ℃, but increased rapidly when the temperature increased to 1 000 ℃. The oxidation rate decreased linearly before 100 h, and then slowed down after 100 h. The pickling process was adjusted according to the formation structure and oxidation rate of scale on site, and the surface quality and production efficiency of steel coil were greatly improved.