Qian CONG
金属学报(英文版)
Five-layered Al/Al-Cu functionally graded material (FGM) was prepared by powder metallurgy technology, and the subsequent heat treatment was carried out for the graded material. The microstructures and distribution of Cu element under pressure sintering (F), solution treatment (T4) and artificial aging treatment (T6) were investigated, and the Vickers hardness and flexural properties of different states were tested. The results showed that sintered compact with dense structure and compositional continuous change was obtained. The second-phase CuAl2 was dispersively distributed along grain boundary of Al matrix. After solution treatment at 503℃ for 3 h, CuAl2 phase obviously decreased and dissolved into the Al matrix, and the flexural strength was thereupon enhanced to 228.5~MPa. With the subsequent aging treatment at 150℃ for 15 h, the majority of flake shaped precipitates Θ" phases were uniformly distributed in the matrix. And the distribution of Cu element became gradual continuous compared to sintered compact. Meanwhile, the flexural strength increased further, which accompanied with the decline of plasticity.
关键词:
Al/Al-Cu graded material
LI Chong-wei
,
CHENG Guo-guang
,
WANG Xin-hua
,
ZHU Guo-sen
,
CUI Ai-min
钢铁研究学报(英文版)
A mathematical model in present study has been established to investigate the effect of Rheinstahl Heraeus (RH) blow argon mode on the decarburization rate in ultra-low carbon steel refining based on the RH equipment of Shougang Qian′an Iron and Steel Co Ltd (SQISCO). The calculated results show that the increase of argon flowrate promotes the carbon elimination from argon gas bubble surface, molten steel free surface in vacuum as well as splash droplet surface, while reduces that from the interior of liquid steel. It has been found the critical turning point of flowrate ascension is at the 5th minute and the optimum blow argon flowrate in later stage is 2100 L/min in accordance with the 2 stages argon blow mode, which have been confirmed in the commercial production in SQISCO.
关键词:
RH
,
vacuum
,
mathematical model
,
argon flowrate
,
decarburization
