The invention provides high-hardness high-wear-resistance high-speed steel. The high-hardness high-wear-resistance high-speed steel is prepared by adopting an injection molding process, and comprisesthe chemical components of, by mass, 1.2-1.5% of C, 8-10% of W, 3-4% of Mo, 3.5-4.5% of Cr, 3.5-4.5% of V, 10-11% of Co and the balance iron and inevitable impurities, wherein carbides of the high-hardness high-wear-resistance high-speed steel are formed by the MC carbide and the M6C carbide, and the type of the MC carbide is VC. The invention also provides a preparation method of the high-speed steel. The high-hardness high-wear-resistance high-speed steel has high hardness and wear resistance, and the application range of the high-hardness high-wear-resistance high-speed steel can be expanded.

High-hardness high-wear-resistance high-speed steel and preparation method thereof

The invention discloses a processing method of a refined 35CrMo alloy steel crystal grain. The processing method comprises following steps: re-melting 35CrMo alloy steel cast ingots in a medium frequency induction furnace to obtain a 35CrMo alloy steel sample with a required size; heating the sample in a box-type resistance furnace, maintaining the temperature, then subjecting the sample to a jumping-up test, after the jumping-up test, immediately quenching the sample in water to obtain a sample with high temperature deformed structures; quenching the sample with high temperature deformed structures in oil, cooling to the room temperature, and carrying out a cyclic ultrasonic quenching-tempering treatment to refine and homogenize the crystal grain tissues so as to obtained the refined 35CrMo alloy steel crystal grain. The microscopic defects of obtained crystal grain are obviously reduced; the size of the crystal grain can reach 10 [mu]m or less, the tissue uniformity is prominently improved, and the comprehensive properties of an alloy member can be strengthened.

Processing method of refined 35CrMo alloy steel crystal grain

The invention discloses a thermal treatment technology for a refined structure of medium-carbon steel and relates to the technical field of thermal treatment. The thermal treatment technology for therefined structure of the medium-carbon steel comprises the following steps that S10, the medium-carbon steel material is heated to 780-810 DEG C, and heat preservation is performed for 2-4 hours; S20,the medium-carbon steel material treated in S10 is forged multiple times; S30, the medium-carbon steel material treated in S20 is cooled to 730-760 DEG C, and heat preservation is performed for 2-4 hours; S40, the medium-carbon steel material treated in S30 is forged multiple times: S50, the medium-carbon steel material treated in S40 is annealed to 540-570 DEG C and finally cooled. During forging treatment, heading is performed in the first direction, and flattening is performed in the second direction. The thermal treatment technology for the refined structure of the medium-carbon steel isadopted for performing heat treatment on the medium-carbon steel material, grains can be obviously refined, and the plasticity and toughness of the medium-carbon steel material can be obviously improved.

Thermal treatment technology for refined structure of medium-carbon steel

The invention provides a manufacturing technology of cold and hot working die steel, and belongs to the technical field of die steel manufacturing. The manufacturing technology comprises the steps ofmedium frequency smelting, external refining, spray forming, first annealing, thermal deformation forging, second-time forging, residual heat annealing after forging, quenching and multiple tempering.According to the manufacturing technology, segregation of components in a steel ingot is restrained in a quite small range through the spray forming step, meanwhile, large particle carbide can be effectively prevented from being formed through two times of forging, the steel impact toughness and plasticity are improved, and the steel quality is improved. The invention further provides the cold and hot working die steel. The cold and hot working die steel comprises 0.55-0.65% of C, 0.85-1.15% of Si, 3.7-4.4% of Cr, 1.8-2.2% of Mo, 1.3-1.7% of V, 1.9-2.2% of W and the balance Fe and impurities.The cold and hot working die steel is uniform and small in structure, large particle carbide is prevented from existing, the die steel has high hardness and high impact toughness which can be equivalent with the toughness of powder steel, and meanwhile the die steel has good plasticity.

Cold and hot working die steel and manufacturing technology thereof

The invention provides high-carbon high-vanadium wear-resistant steel. The high-carbon high-vanadium wear-resistant steel is prepared from the following chemical components in percentage by mass: 2.0to 3.0% of C, 3.5 to 5.0% of W, 2.0 to 4.0% of Mo, 4.0 to 5.0% of Cr, 7.0 to 9.0% of V, and the balance of iron; the carbide composition of the high-carbon high-vanadium wear-resistant steel is MC carbide and M6C carbide, wherein the type of the MC carbide is VC. The high-vanadium wear-resistant steel provided by the invention has a uniform microstructure, excellent wear resistance, hardness and processing structure property, and wide application. The cost of the preparation method provided by the invention is lower than that of a powder metallurgy process, and the production cost is reduced wholly.

Yang Yunfeng

Papers

Cold and hot working die steel and manufacturing technology thereof

High-carbon high-vanadium wear-resistant steel and preparation method thereof