CAJ | 학술논문

研究了微量稀土对Cr21Ni11N奥氏体耐热不锈钢高温热塑性及高温持久性能的影响.结果表明:在750～1250℃范围内,稀土显著提高耐热钢的热塑性,消除800℃的塑性低凹区,扩宽安全热加工温度范围近75℃.稀土显著延长耐热钢的高温持久寿命约3～5倍,并提高持久断裂塑性.钢中添加稀土后,其蠕变断裂机制由楔形裂纹为主的机制逐渐转变为空洞裂纹为主的机制,高温持久断口附近的楔形裂纹明显减少,且断口呈典型的韧窝状塑性断口特征.
연구료미량희토대Cr21Ni11N오씨체내열불수강고온열소성급고온지구성능적영향.결과표명:재750～1250℃범위내,희토현저제고내열강적열소성,소제800℃적소성저요구,확관안전열가공온도범위근75℃.희토현저연장내열강적고온지구수명약3～5배,병제고지구단렬소성.강중첨가희토후,기연변단렬궤제유설형렬문위주적궤제축점전변위공동렬문위주적궤제,고온지구단구부근적설형렬문명현감소,차단구정전형적인와상소성단구특정.
The effect of minor RE addition on hot duc-tility and creep rupture properties of austenitic heat-re-sistant stainless steel Cr21Ni11N were investigated. The experimental results showed that the hot ductility of the alloy in the range of 750 ～ 1250 ℃ was im-proved significantly, and the ductility drop at 800 ℃ was eliminated. And also the safe temperature for hot working was extended nearly 75℃ by adding RE ele-ments in this steel. Moreover, the creep rupture lives of the tested steels were extended considerably about 3～5 times, and the creep rupture ductility was in-creased. After adding minor RE, the creep mecha-nism was changed gradually from wedge crack to creep voids, the wedge cracks were reduced significantly near fracture surface, and the fracture morphology was classical characteristics of dimple fracture.