锅炉用TP347HFG和内壁喷丸TP347H奥氏体耐热钢抗蒸汽氧化性能对比研究

Comparative Investigation on Steam Oxidation Resistance of TP347HFG and Inner Surface Shot-peened TP347H Austenitic Heat Resistant Steel for Boilers

对TP347HFG和内壁喷丸TP347H钢管试样在650℃、27MPa条件下进行不同时长的抗蒸汽氧化试验,并分析了氧化膜的横截面形貌、微观结构、元素分布和物相。结果表明:TP347HFG的氧化速率遵循幂指数规律;内壁喷丸TP347H表面大部分区域形成了富Cr氧化膜薄层、局部区域生成较厚岛状氧化物;TP347HFG氧化物的内层为(Ni,Fe)Cr_2O_4 、外层为Fe3O4和Fe_2O_3,内壁喷丸TP347H氧化物为Cr_2O_3和FeCr_2O_4 ;在所试验时间内,内壁喷丸TP347H的抗蒸汽氧化性能优于TP347HFG。

Steam oxidation resistance tests of TP347HFG and inner surface shot-peened TP347H boiler tube samples were conducted at 650℃and 27 MPa for different hours,while the cross section morphology,microstructure,elements distribution and phases of oxide layers were analyzed.Results show that the oxidation rate of TP347HFG follows the exponential oxidation rule.On the inner surface of shot-peened TP347H tubes,a thin layer of Cr-rich oxide film forms in most areas,while thicker island-like oxide film forms in local region.The inner layer of oxides on TP347HFG tubes mainly consists of(Ni,Fe)Cr2O4,and the outer layer is made up of Fe3O4 and Fe2O3,while Cr2O3 and FeCr2O4 are included in the oxides on inner surface shot-peened TP347H tubes.Comparatively,the inner surface shot-peened TP347H is proved to have better steam oxidation resistance than TP347HFG by the test.