EFFECTS OF delta-FERRITE ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES IN A TUNGSTEN-ALLOYED 10%Cr ULTRA-SUPERCRITICAL STEEL
文献类型：期刊论文
| 作者 | Hu Xiaoqiang; Xiao Namin; Luo Xinghong; Li Dianzhong |
| 刊名 | ACTA METALLURGICA SINICA
 |
| 出版日期 | 2009-05-01 |
| 卷号 | 45期号:5页码:553-558 |
| 关键词 | delta-ferrite ultra-supercritical steel microstructure mechanical property |
| ISSN号 | 0412-1961 |
| 通讯作者 | Li Dianzhong(dzli@imr.ac.cn) |
| 英文摘要 | The tungsten-alloyed 10%Cr (mass fraction) steel, one of the advanced 9%-12%Cr steels, has been widely considered as a preferred candidate for making key components in ultra-supercritical (USC) steam turbines. Due to large amounts of ferrite former in the steel, the formation temperature of delta-ferrite is lowered down, and therefore delta-ferrite is apt to be produced during hot working. However, understanding of the formation mechanism of delta-ferrite and its influence on the mechanic properties of ultra-supercritical steels is still either ambiguous or conflicting. To clarify this problem., in this paper, the microstructure and morphology of delta-ferrite were investigated by optical microscope, scanning electron microscope and energy dispersive spectrum (EDS) analysis. Also, the mechanical properties including the tensile strength, ductility and impact toughness of the studied steel with various volume fraction of delta-ferrite were tested at room temperature. Experimental results indicate that the transformation mechanism of delta-ferrite is closely dependent on the austenitizing temperature. Extremely small amounts of acicular delta-ferrite preferentially nucleate and grow inside the prior austenite grains, if the austenitizing temperature is just a little higher than the equilibrium transformation point of delta-ferrite. While, as the austenitizing temperature increases further, some polygonal delta-ferrites subsequently form on prior grain boundaries and grow quickly. Meanwhile, the repartitioning of solute elements occurrs between delta-ferrite and prior austenite. Both acicular and polygonal delta-ferrites will damage the impact toughness of the studied steel. And in spite of its few amounts, the detrimental effect of acicular delta-ferrite on the mechanical properties, especially the impact toughness, is more severe than that of polygonal delta-ferrite. Additionally, the tensile strength and the axea reduction of the studied steel decrease as the amount of delta-ferrite increases, while the elongation hardly changes with the amount of delta-ferrite increasing. As a conclusion, accurately controlling the austenitizing temperature to prevent from the formation of any delta-ferrite is not only necessary but, also very important in obtaining perfect overall mechanical properties. |
| WOS研究方向 | Metallurgy & Metallurgical Engineering |
| 语种 | 英语 |
| WOS记录号 | WOS:000266627900007 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.imr.ac.cn/handle/321006/98486]  |
| 专题 | 金属研究所_中国科学院金属研究所 |
| 通讯作者 | Li Dianzhong |
| 作者单位 | Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China |
| 推荐引用方式 GB/T 7714 | Hu Xiaoqiang,Xiao Namin,Luo Xinghong,et al. EFFECTS OF delta-FERRITE ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES IN A TUNGSTEN-ALLOYED 10%Cr ULTRA-SUPERCRITICAL STEEL[J]. ACTA METALLURGICA SINICA,2009,45(5):553-558. |
| APA | Hu Xiaoqiang,Xiao Namin,Luo Xinghong,&Li Dianzhong.(2009).EFFECTS OF delta-FERRITE ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES IN A TUNGSTEN-ALLOYED 10%Cr ULTRA-SUPERCRITICAL STEEL.ACTA METALLURGICA SINICA,45(5),553-558. |
| MLA | Hu Xiaoqiang,et al."EFFECTS OF delta-FERRITE ON THE MICROSTRUCTURE AND MECHANICAL PROPERTIES IN A TUNGSTEN-ALLOYED 10%Cr ULTRA-SUPERCRITICAL STEEL".ACTA METALLURGICA SINICA 45.5(2009):553-558. |
入库方式： OAI收割
来源：金属研究所
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