材料期刊网

Failure Analysis of WC-3.5wt%Co Cemented Carbides in Mining Applications

WANG Junyuan , WANG Haipeng , WANG Huajun , HE Ling , LUO Wei , ZHANG Yan , WANG Hongfu

武汉理工大学学报-材料科学版(英文版) doi:10.1007/s11595-015-1308-1

关键词:

Influence of Mineral Admixtures on the Electro-deposition Healing Effect of Concrete Cracks

CHU Hongqiang , JIANG Linhua , YOU Lushen , XU Ning , SONG Zijian , ZHANG Yan

武汉理工大学学报-材料科学版(英文版) doi:10.1007/s11595-014-1071-8

关键词:

Influence of Air-Knife Wiping on Coating Thickness in Hot-Dip Galvanizing

ZHANG Yan , CUI Qi-peng , SHAO Fu-qun , WANG Jun-sheng , ZHAO Hong-yang

钢铁研究学报(英文版)

In hot-dip galvanizing process, air jet wiping control is so crucial to decide the coating thickness and uniformity of the zinc layer on the steel strip. The mathematical models developed predict the zinc coating thickness as a function of pressure and shear stress. The required pressure and shear stress profile on the strip surface were calculated using regression analysis, and carried out using numerical simulation as FLUENT, a finite element analysis software. The influences of the outlet pressure, the nozzle to strip distance, the slot opening, the edge baffle plate, as well as the tilting angle of air knife were discussed. Combining with these results and regression analysis on the practical data, four first-order polynomial multi-parameter models were established for different targeted coating thicknesses with better regression coefficients. The validated model was used to carry out sensitivity analysis to determine the favorable controlling regime for the air jet wiping process.

关键词: hot-dip galvanizing , air knife , air jet wiping , numerical simulation , coating thickness

Effects of Al on Microstructure and High-Temperature Wear Properties of Austenitic Heat-Resistant Steel

ZHANG Yan , SUN Yu-fu , ZHAO Jing-yu , GUAN Shao-kang

钢铁研究学报(英文版)

Microstructure and high-temperature dry sliding wear at 600 ℃ in ambient air of austenitic heat-resistant steel ZG40Cr25Ni20 with different contents (mass percent) of Al (0 to 710%) have been investigated. The results show that microstructures of 468% and 710% Al addition content consist of the matrix and reinforcement of intermetallic compound γ′ and carbide, while microstructures of ZG40Cr25Ni20 without Al and with Al of 168% are absent of γ′. Higher wear resistance than the original ZG40Cr25Ni20 alloy is achieved in alloys with higher content of Al under the same high-temperature wear test condition. The wear rates of Fe-25Cr-20Ni-710Al and Fe-25Cr-20Ni-468Al are only 2083% and 4583% of that of Fe-25Cr-20Ni, respectively. Heat-resistant steels with higher contents of Al (472% and 710%) have higher hardness than those with lower contents of Al (168% and 0). Wear mechanisms of ZG40Cr25Ni20 are considered as severe plough plastic deformation and slight adhesive. However, wear mechanisms of Fe-25Cr-20Ni-468Al are light micro-cutting and oxidation-wear, while that of Fe-25Cr-20Ni-710Al are severe adhesive transfer and oxidation-wear.

关键词: austenitic heat-resistant steel , Al , microstructure , high-temperature sliding wear , mechanism