The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigate...The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.展开更多
A high alloyed Vanadis4 （V4） steel was produced by spray forming process in Baosteel, and the microstructure of the as-sprayed steel and its evolution during hot rolling and annealing processes were characterized. I...A high alloyed Vanadis4 （V4） steel was produced by spray forming process in Baosteel, and the microstructure of the as-sprayed steel and its evolution during hot rolling and annealing processes were characterized. It was found that the as-sprayed V4 steel has a homogeneous and fine scale rrficrostructure with uniform dispersion of carbides. The hot rolling temperature is the key factor in controlling the evolution of type, morphology and distribution of carbides, as well as the matrix microstructure of the as-rolled steels. The optimized processing parameters for the as-sprayed V4 steel are rolling at 1050℃ and then annealing at 900℃. The microstructural evolution mechanisms during hot rolling and annealing are determined according to the microstructural analyasis of the material at different stages.展开更多
文摘The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.
文摘A high alloyed Vanadis4 （V4） steel was produced by spray forming process in Baosteel, and the microstructure of the as-sprayed steel and its evolution during hot rolling and annealing processes were characterized. It was found that the as-sprayed V4 steel has a homogeneous and fine scale rrficrostructure with uniform dispersion of carbides. The hot rolling temperature is the key factor in controlling the evolution of type, morphology and distribution of carbides, as well as the matrix microstructure of the as-rolled steels. The optimized processing parameters for the as-sprayed V4 steel are rolling at 1050℃ and then annealing at 900℃. The microstructural evolution mechanisms during hot rolling and annealing are determined according to the microstructural analyasis of the material at different stages.
