Zhuangqi HU Huaming WANG Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
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ChinaY.Murata M.Morinaga Toyohashi University of Technology
,
Toyohashi
,
Aichi
,
440 Japan
材料科学技术（英文）
The solidification microstructures and solute segregation of a newly developed hot corrosion resistant single-crystal Ni-base superalloy were investigated with a zone-melting and ultra-high thermal gradient unidirectional solidification apparatus.Compared with the microstructures solidified at conventional low thermal gradient conditions,the dendrite arm spacings,the interdendritic microporosity and γ/γ' eutectic,and the severity of solute segregation of the single-crystal superalloy solidified at ultra-high thermal gradient conditions were considerably reduced.It was shown that the microstructure solidified under ultra-high thermal gradient condition is ideal for the full exploitation of the excellent property potentials of single-crystal superalloys.
关键词:
single-crystal superalloy
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null
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null
K. Mii (Sumitomo Metal Industries
,
Ltd.
,
1-t-3 Otemachi
,
Tokyo 100
,
Japan)M Amano (National Research Institute for Metals
,
1-2-1 Sengen
,
Tsukuba 305
,
Japan)
金属学报(英文版)
The R & D of hydrogen absorbing alloys in Japan started in the early 1970s.Many alloys such as TiMm1.5 based alloys, Fe-Ti-O alloys (e.g. FeTi1.15 O0.024) andthe(mischmetal)Ni5 based alloys (e.g. MmNi4.5 Cr0.46 Mn0.04) were developed by the early 1980s. The application of these alloys to hydrogen storage, heat storage, heat pump, hydrogen purification and motor vehicles has been tried in many iaboratories,and the various techniques for using hydrogen absorbing alloys have been developed.The standarkization of evaluation methods for hydrogen absorbing alloys has been promoted by the Ministry of International Trade and Industry (MITI), and four of them were established as Japanese Industrial Standard (JIS).Alloys for Ni-Metal Hydride batteries have been extensively investigated since 1987in Japun. Mm-Ni-Co-Al-Mn alloys (e.g. MmNi3.55 Co0.75Al0.9Mn0.4) have been devel-oped and commereialized since 1990. The amount of production of small-size Ni-MH batteries in 1995 was about three hundred milliion in number and about one hundred billion yen. The R & D for higher enerpy-density Ni-MH batteries is intensively in progress.MITI and STA (Science and Technology Agency) have promoted the R & D of hydro-gen absorbing alloys in Japan by carrying out the national projects such as Sunshine Program (MITI: 1974-1993) and Utilization of Wind Engeray (STA 1980-1985). The New Sunshine Program (MITI 1993-2020) have started in 1993. This program con-tains the application of hydrogen absorbing alloys to Economical- Enerpy- City System and to We-NET (International Clean Energy System of Technology Utilizing Hydro-gen: World Energy Network.
关键词:
hydrogen absorbing alloy
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null
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null
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null
孔祥华
,
唐晋
,
孙瑞虹
,
赵广宏
,
孙彦辉
,
袁国华
,
孙华
,
李翔
材料热处理学报
研究了SCM440钢的开裂敏感性与轧后冷却过程中的温度、脱碳程度的关系。结果表明,轧后冷却过程中SCM440大盘条在表层以下30μm以内的区域产生的微裂纹引起了冷镦开裂。在轧后冷却过程SCM440盘卷表面发生脱碳。微裂纹主要在750～800℃范围内产生,由于在这个温度范围内SCM440钢处于两相区,发生了铁素体相变,在表层形成铁素体全脱碳层,最后由于组织应力形成了沿铁素体晶界扩展的微裂纹。
关键词:
开裂敏感性
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脱碳
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组织应力
王双锁
,
刘家泳
,
孙宇
,
杨永昌
中国冶金
对CTP440Ⅵ穿轧机进行了简单介绍,详细讲述了CTP440Ⅵ穿轧机穿孔工具的设计依据和计算过程,包括锥形轧辊的直径、长度、入口锥和出口锥,顶头的直径、长度、工作锥、均整段、反锥,导盘的入口半径、出口半径及厚度,并分别给出了设计图.最后通过难变形高合金钢13Cr的穿孔试验验证了穿孔工具的设计是合理的,完全满足科研开发的需求.
关键词:
二辊斜轧穿孔
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锥形轧辊
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顶头
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导盘
吴昊
,
张桂香
,
赵文聪
电镀与精饰
doi:10.3969/j.issn.1001-3849.2015.03.005
基于磁力研磨,采用雾化快凝法制备的Al2O3系球形磁性磨料,选取440c不锈钢进行光整加工.采用正交试验设计,选用不同粒度磨料对工件进行磁力研磨,并得出优化加工参数.试验结果表明,优化参数为主轴转速2 500 r/min、加工间隙1.5mm、进给速度60 mm/min、磨料填充量2.0g.440c不锈钢工件微观表面形貌和微观纹理得到改善,表面粗糙度由0.450μm下降到0.043μm,达到镜面效果.表明磁力研磨对440c不锈钢有良好的光整加工效果,其疲劳强度和耐腐蚀性得到不同程度的提高.
关键词:
磁力研磨
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正交试验设计
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440c不锈钢
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表面形貌
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表面粗糙度
陈斌锴
,
张启富
,
郝晓东
,
仲海峰
,
俞钢强
材料热处理学报
通过SEM和AFM研究了IF440高强钢钢板入锅温度和浸镀时间对镀层抑制层组织结构的影响.结果表明,抑制层的组织结构分为粗晶区Fe2 Al5相和细晶区FeAl3相,并且随钢板入锅温度升高和浸镀时间增加,细晶区晶粒逐渐长大,直至与粗晶区晶粒尺寸一致,抑制层晶粒粗化,致密性下降致使其抑制作用降低.IF440高强钢适宜热镀锌工艺:钢板入锅温度为460 ～470℃,浸镀时间为4～6s.
关键词:
IF440高强钢
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热镀锌工艺
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抑制层
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组织
谭志诚
,
王庄
金属学报
<正> 我们采用自行建立的精密自动绝热量热装置(见图1),将加热器的绕线Karma合金丝作试样,稍加改进量热操作技术,精确测定了70—440K温度区间Karma合金丝的电阻率。 先将图1中薄壁紫铜管加热器涂绝缘漆,螺旋双绕Karma合金丝,再涂漆固定,注意防止漆层剥落。引出丝的末端以备测量电压电流。铜管
关键词:
Seok-Hwan Ahn
,
Insup Lee
材料科学技术（英文）
Plasma radical nitriding was performed to harden the surface of SCM440 steel for 1-10 h at temperature range of 450-550℃. This process involved the use of NH3 gas instead of N2 gas employed for the well-established plasma nitriding method. No compound layer was formed during this process except the experiment carried out at 500℃ for 10 h. The main phase produced in the diffusion zone was identified to be γ′-Fe4(N, C). A diffusion depth increased with increasing treatment temperature and time (up to about 250 μm). The surface hardness of radical nitrided layer was about two times higher than that of the untreated surface. The tensile test was carried out to estimate the mechanical properties of surface-hardened SCM440 steel prepared at various plasma radical nitriding treatment time and temperature. The influence of radical nitriding treatment on the tensile strength of the specimen was found to be insignificant. The highest value of the ultimate tensile strength was obtained in the experiment carried out at 500℃ for 1 h. However, the elongation was greatly affected by the radical nitriding processing parameters. The maximum value of elongation, which is equal to about 18.1%, was also obtained under the condition of 500℃ for 1 h.
关键词:
Plasma radical nitriding
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null
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null
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