GUO Shouren LU Dezhong GUO Jianting Institute of Metal Research
,
Academia
,
Shenyang
,
ChinaWU Xi Fushun Steel Works
,
Fushun
,
China Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The mechanical properties and microstructure of an Fe-base superalloy GH35A have been examined after aging at 650—750℃ for 100—10000 h.The tensile strength of the alloy changes no more with aging temperature and the time at room temperature,but the ductility and impact toughness at room temperature,as well as the stress-rupture life up to 700℃ de- crease slowly during aging up to 10000 h The initiation time to worsen its properties becomes shorter as the aging temperature rises.The variation of the mechanical properties of the alloy was found mainly depending on the formation,morphology,distribution and characteristic of the σ-phase precipitation.
关键词:
superalloy
,
null
,
null
,
null
,
null
彭宁琦
,
唐广波
,
刘正东
,
吴秀月
金属学报
doi:10.3321/j.issn:0412-1961.2009.03.013
根据Aaronson提出的超组元模型,借助Ae3的实验数据,提出了修正的置换型元素Xi(Xi=Si,Mn,Ni,Co,Mo,Al,Cu,Cr)的Zener两参数,修正中考虑了合金元素间的交互作用.修正后的超组元模型的预测精度明显改善:Ae3计算值与实验值的标准差为10.8℃,与Thermo-Calc计算值的标准差为2.35℃;Ae1计算值与实验值的标准差为6.8℃.按照马氏体相变热力学的计算方法,采用经修正的参数计算了马氏体相变开始温度Ms,提高了Ms点的预测精度,计算值与实验值的标准差为25.3℃.
关键词:
相变
,
热力学
,
超组元模型
,
相变平衡温度
盛广
,
杨志刚
金属学报
根据Fe--C--Xi合金系的正平衡和准平衡热力学模型，推导了简便的奥氏体--铁素体相变驱动力计算解析式。根据公式, 代入合金原始成分和Ae3温度, 即可准确计算正平衡和准平衡模式下的奥氏体--铁素体相变驱动力。采用这一方法计算了Fe--C--Mn--Si--Ni--Cr--Mo--Cu八元系的正平衡和准平衡奥氏体--铁素体相变驱动力。
关键词:
正平衡
,
null
,
null
,
null
LI Changsheng
,
YANG Hua
,
WANG Yanfang
,
et al
钢铁研究学报(英文版)
Fe-3%Si steel strip was experimental produced by thin slab casting and rolling (TSCR) process in the laboratory. The microstructure and texture of hot rolled strip by different total reduction and rolling schedule was observed through EBSD technique and X-ray diffraction method. The changeable rule of texture density on the α、ε and γ, and fibers was analyzed. When the total reduction was increased from 82.9% to 97.1%，the gradient of microstructure and texture for A steel surface layer and center layer was found, {001}‹110› texture had higher intensity, and {001}‹110› texture was changed to{110}‹001›和{112}‹111›. The texture distribution with different reduction schedule for B steel was basically similar, but the Goss texture orientation density and volume fraction for B steel were higher, the hot rolling reduction schedule of C1 was effective to the formation of Goss texture. The research works were useful theoretical basis and reference data to develop electrical steel by thin slab continuous casting and direct rolling technology.
关键词:
Silicon steel;texture;hot rolling;thin Slab;Continuous casting and direct rolling
材料科学技术（英）
The grain structures and the precipitates in the solidification microstructure of the ultra pure 17 wt% Cr ferritic stainless steels with different Ti and/or Nb micro-alloying were investigated both experimentally and theoretically. It was found by the grain structure observation that the addition of Ti or Nb to the steel reduced the grain size (D) and elongation factor (E), and improved the equiaxed grain proportion (P) and globularity factor (xi). Among the four steels studied, the minimum grain size and maximum equiaxed grain proportion were obtained by jointly adding both Ti and Nb to the steel. The SEM observation indicated that several kinds of precipitations, such as TiN, MC (rich in Nb), Laves phase (Fe(2)Nb) and so on, formed in the corresponding steels. In addition, the results calculated using the Thermo-Calc software illustrated that TiN precipitates in the liquid at proper Ti and N contents. Meanwhile, the solidification interval (Delta T) was enlarged by the addition of Ti or Nb, and the effectiveness of Nb was stronger than Ti. Based on the experimental and calculation results, the mechanisms of grain refinement and increment in equiaxed grain proportion were discussed.
关键词:
Ultra pure ferritic stainless steel;Micro-alloying;Solidification;structure;Titanium;Niobium;high-strength steels;precipitation behavior;texture formation;microalloyed steels;grain-refinement;microstructure;recrystallization
