Xianghua LIU
,
Ge YAN
,
Liya CUI
,
Shaoxiong ZHOU
,
Wu ZHENG
,
Ailing WANG
,
Jinchang CHEN
材料科学技术（英文）
Sm22Co78/Fe65Co35/Sm22Co78/Fe65Co35 multilayer films were prepared by magnetron sputtering. The temperature dependence of coercivity (H-c), remanence (M-r) and reduced remanence (M-r/M-s) has been measured. The coercivity decreases with increasing of temperature. The remanence decreases with increasing the temperature from 26 to 100 degrees C, and then increases with continuously increasing the temperature from 100 to 150 degrees C. The reduced remanence increases with increasing the temperature.
关键词:
Fengli SUI
,
Liqing CHEN
,
Xianghua LIU
,
Lintao WANG
,
Wei LI
金属学报(英文版)
doi:10.1016/S1006-7191(08)60074-5
A coupled thermo-mechanical model containing metal flow and temperature field for calculating temperature variation has been developed on fourteen-pass hot continuous rolling of round rod for Inconel 718 alloy using 3D elastic-plastic finite element method (FEM). The temperature of characteristic analysis points in the intermediate cross-section of the workpiece has been simulated at initial temperature ranging from 960 to 1000 ℃ and initial velocity in range of 0.15-0.55 m．s-1. Based on finite element analysis and microstructural observation in cylindrical hot compression experiments, the appropriate hot continuous rolling technologies have been designed for rod products with different diameters. For a real rolling practice, the simulated surface temperature was examined and is in good agreement with the measured one.
关键词:
Hot continuous rolling
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null
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null
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null
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Shengjie YAO
,
Shengjie YAO
,
Xianghua LIU
,
Guodong WANG
金属学报(英文版)
doi:10.1016/S1006-7191(08)60064-2
Ultrafine austenite grains (UFAGs) with size of 1-5 μm were prepared through repetitive treatment, four times, of rapid heating and quenching, and the growth behaviors of these UFAGs during both the reheating and cooling stages were investigated. The results indicated that UFAGs without pinning particles appeared with significant coarsening when the reheating temperature reached 1000℃. Although coarsening still occurred in the cooling stage, the growth was obscured during the isothermal holding process at temperatures between 900 ℃ and Ar3
关键词:
Ultrafine austenite grain
,
null
,
null
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Huawei ZHANG
,
Lizhong LIU
,
Ping HU
,
Xianghua LIU
金属学报(英文版)
Residual stress developed during the rolling process of tailor rolled blank (TRB) can affect the springback of finished parts considerably. Springback characteristics of unannealed and annealed TRBs were investigated by means of numerical simulation and experiments taking U-Channel as an example. TRBs were annealed by the annealing process (700℃, holding time 10h), then stamping and springback processes of unannealed and annealed TRBs were simulated, and corresponding experiments were also carried out. Effects of the transition zone length, the blank thickness, the friction coefficient and the die clearance on the springback of TRB were analyzed. The results demonstrate that the springback of TRB annealed at 700℃ for 10 h reduces significantly. For unannealed and annealed U-Channels, the springback of TRB U-Channel is in direct proportion to the die clearance and is in inverse proportion to the transition zone length, the blank thickness and the friction coefficient. Springbacks of the thinner monolithic (uniform thickness) blank, the thinner side of TRB, the thicker side of TRB and the thicker monolithic blank are sorted in descending order.
关键词:
Tailor rolled blank
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null
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