| 引用本文: | 夏志新,张弛,柳文波.P92钢表层纳米组织的热稳定性[J].材料科学与工艺,2014,22(3):108-113.DOI:10.11951/j.issn.1005-0299.20140319. |
| XIA Zhixin,ZHANG Chi,LIU Wenbo.Thermal stability of nanocrystalline microstructure in P92 heat resisting steels[J].Materials Science and Technology,2014,22(3):108-113.DOI:10.11951/j.issn.1005-0299.20140319. |
|
| 摘要: |
| 本文通过表面纳米化处理(SMAT)在P92钢表层中形成纳米组织结构,研究了回火温度对表层纳米组织演化行为和析出行为的影响.结果表明:淬火态和回火态P92钢组织经过SMAT处理后沿深度方向依次是纳米层、剧烈变形层、最终过渡到正常组织.随后分别研究了淬火和回火态SMAT试样经不同温度回火后微观组织的再结晶及长大行为.经SMAT处理的铁素体纳米晶粒在550 ℃时仍能保持较好的纳米结构,甚至高达650 ℃时表层晶粒仍为纳米晶,当温度超过760 ℃时表层组织发生显著的再结晶和晶粒长大现象.纳米晶界能抑制淬火态P92钢在较低温度回火时M23C6碳化物的析出.纳米组织提高了高温回火过程中合金元素在铁素体中的扩散速率,加速了M23C6碳化物的长大过程.不同温度回火过程中SMAT纳米层中析出行为的变化将在本文中详细描述. |
| 关键词: P92耐热钢 纳米组织 热稳定性 高温氧化 |
| DOI：10.11951/j.issn.1005-0299.20140319 |
| 分类号:TG142.73 |
| 基金项目: |
|
| Thermal stability of nanocrystalline microstructure in P92 heat resisting steels |
|
XIA Zhixin1, ZHANG Chi2, LIU Wenbo2
|
|
(1.Shagang School of Ion and Steel, Soochow University, Suzhou 215021, China; 2.Department of Materials Science and Engineering, Tsinghua University, Beijing 100084,China)
|
| Abstract: |
| High temperature oxidation resistance of P92 steels can be further improved by the nanocrystalline microstructure of a surface layer induced by surface mechanical attrition treatment. Thermal stability of nanocrystalline microstructure was also studied. The results indicate that there are nanocrystalline layer, severely deformed surface layer and matrix along depth in the surface layer of the quenching and tempering state SMAT specimens. The microstructure is still nanocrystalline at 550 ℃ and 650 ℃. Precipitation behaviors of carbides could be inhibited in the nanocrystalline layer at the lower tempering temperature, however, the nanocrystalline accelerate the coarsening of carbides at 760 ℃. The recrystallization and abnormal growth of ferritic grains are attributed to the change of strain along depth in the surface layer at 760 ℃. |
| Key words: P92 steels nanocrystalline thermal stability high-temperature oxidation |
