36results about How to "Improve as-cast structure" patented technology

The invention discloses high-strength aluminum alloy for a motor train unit gearbox and a preparation method of the high-strength aluminum alloy. The high-strength aluminum alloy comprises the following components in percentage by weight: Mg, Cu, Zn, Fe, Si, Ti, Cr, Te, Ge, Nb, Er, Mo, Ce, Sc, Zr, Sr and the balance of Al, wherein content of each of other impurity elements is equal to or less than 0.05%, and total content of other impurity elements is equal to or less than 0.2%. According to the invention, the alloy components are reasonable, the technology is optimized, and the obtained high-strength aluminum alloy has the advantages of light weight, high strength, corrosion resistance, low possibility of cracking and the like and can meet the performance requirements of the motor train unit gearbox.

The invention discloses a method for preparing a high-strength A356 alloy. A novel low-cost, high-strength A356 alloy is prepared by means of modification treatment, solid solution strengthening, fine-grain strengthening and second phase strengthening. (1) Improve the as-cast structure of the alloy by adding modifiers Ba and Zr; (2) Use high-pressure solidification technology to prepare high-pressure solidified A356 with finer grains and higher supersaturated solubility of Mg, Si and other elements in the matrix (3) Further enhance the strength of the high-pressure solidified A356 alloy through aging strengthening.

The invention belongs to the technical field of hot work die steel, and discloses a modified 4Cr5MoSiV1 hot work die steel and a preparation method thereof. Smelting at 1450-1550 ℃, casting under argon protection, and cooling naturally after casting to obtain steel ingots; after remelting the steel ingots with protective atmosphere electroslag remelting technology, heat preservation at 1250 ℃, and then forging and cooling; It was kept at 850°C and then cooled to room temperature in sections with the furnace to obtain modified 4Cr5MoSiV1 hot work die steel. The invention improves the yield of rare earth in steel by adding rare earth intermediate alloy and utilizes the interaction of various components; reduces the segregation of Cr, Mo, V and other alloy elements at the grain boundary, and achieves the purpose of reducing dendrite segregation; The as-cast structure of the steel is improved, and the mechanical properties such as the fatigue life of the steel are improved.

The invention discloses a preparation method of a high corrosion resistant and high wear resistant aluminium alloy profile for an engine cylinder cover. the aluminium alloy profile is composed of the following elements, by weight, 9.4-10.8% of Si, 0.7-1.4% of Cu, 0.4-0.8% of Mg, 0.15-0.25% of Fe, 0.3-0.6% of Cr, 0.05-0.1% of Mn, 0.02-0.04% of Zn, 0.01-0.02% of Ni, 0.03-0.05% of As, 0.025-0.045% of Sn, 0.02-0.03% of Cd, 0.015-0.025% of Hf, 0.005-0.01% of B, 0.02-0.04% of Ce, 0.01-0.03% of Yb and the balance Al. The aluminium alloy profile prepared by the above method has excellent comprehensive properties and high high-temperature strength, can operate at 250-300 DEG C for a long time, has excellent corrosion resistance and wear resistance, and has a wide application prospect.

The invention discloses a process for producing die steel by utilizing a converter continuous casting mode. The process comprises a steel making continuous casting process and a steel rolling process. The steel making continuous casting process comprises the following process steps of: converter smelting, LF (Ladle Furnace) refining, continuous casting, slow cooling and other process steps; and the steel rolling process comprises the following process steps of: heating, scale removal by using high pressure water, rolling, straightening, stacking, slow cooling and other steps. By using the die steel produced by the invention, the contents of gas and occluded foreign substances in the die steel can be reduced, the thermal stress and the structural stress for slowing a steel blank down are eliminated, a thick and nonuniform cast structure inside the steel blank is improved, and the problems of flaw detection disqualification and finished product crack of the die steel are solved. By using the process, the aim of producing the die steel by using a converter is achieved, the production cost is reduced, and the economic benefit is increased.

A method for smelting ultra-advanced duplex stainless steel made of CD3MWN, which is designed for the internal control composition during smelting of duplex stainless steel; wherein C≤0.030 wt%, Si≤0.90 wt%, Mn is 1.20-2.50 wt%, P≤0.020 wt%, S≤0.015 wt%, Cr 26.2-27.5 wt%, Ni 6.2-7.6 wt%, Mo 2.2-3.4 wt%, Cu≤0.80 wt%, W≤0.80 wt%, N 0.32-0.38 wt%, B is 0.0010-0.0100 wt%, Ba is 0.0002-0.0100 wt%, Ce+La is 0.005-0.030 wt%; %Cr+3.3(%Mo+0.5%W)+16%N≥45, precise control of trace The content of elements B, Ba, Ce, and La; increase the N content to more than 0.30%, and at the same time avoid nitrogen pores in the casting; minimize the content of harmful elements such as sulfur, oxygen, hydrogen and other elements, and improve the liquid steel. purity. The poured casting has high strength and excellent corrosion resistance. The ratio of ferrite phase and austenite phase in stainless steel is close to 50%. The service life of the casting is prolonged, the manufacturing cost is greatly reduced, and the goals of energy saving, consumption reduction, and environmental protection are realized.

The invention discloses an abrasion-proof and corrosion-resistant nickel-based alloy wire and a preparation method thereof. The alloy wire comprises the following components: 17-21% of C, 20-25% of Co, 1.8-2.2% of W, 6.4-9.5% of Mo, 1.4-1.8% of Al, 3.2-4.5% of Ti, 0.1-0.5% of Nb, 0.1-0.5% of Hf, 1.2-1.8% of Ta, 0.03-0.06% of Re, 0.01-0.05% of Ce, 0.02-0.1% of C, 0.005-0.015% of B, 0.02-0.07% of Zr, 0.005-0.008% of Mg, and the balance Ni. The preparation technology of the alloy comprises the steps of vacuum smelting, remelting, forging, hot rolling, drawing, solid solution treatment and aging treatment, namely, raw materials are prepared and smelted based on mass percent and then smelted; the smelted materials are forged and rolled into obtain alloyed wire rods; the alloyed wire rods are drawn at a plurality of times to obtain phi 0.05-0.4mm alloy wires; finally the alloy wires are subjected to solid solution treatment and aging treatment. The abrasion-proof and corrosion-resistant nickel-based alloy wire can be used as a brush wire material for brush sealing of an aircraft engine, a gas turbine, etc., thus the brush sealing effect can be effectively improved, and the service life can be prolonged.

The invention relates to a steel forging with an ultra-high strength and an ultra-high low-temperature impact on the box body of a fracturing pump valve and a manufacturing method of the steel forging. The steel forging is used for solving the technical problems of low mechanical performance, bad corrosion resistance, short service life, and high cost of the existing steel materials. The steel forging comprises the following chemical ingredients in percentage by weight: 0.25-0.3% of C, 0.15-0.35% of Si, 0.6-0.9% of Mn, 1.8-2.2% of Cr, 4.05-4.25% of Ni, 0.46-0.6% of Mo, 0.12-0.18% of V, not greater than 0.01% of P, not greater than 0.01% of S, not greater than 0.12% of Nb, not greater than 0.12% of Re, not greater than 0.2% of Cu, not greater than 0.00016% of H, not greater than 0.0035% of O, not greater than 0.0065% of N, and the balance of Fe and inevitable impurities. The steel forging disclosed by the invention can be used in the fields of petroleum exploitation and shale gas exploitation.

The invention discloses a high-temperature oxidation resistant wearproof Co-based alloy wire and a preparation method thereof. The high-temperature oxidation resistant wearproof Co-based alloy wire comprises the following ingredients: 13-17% of Cr, 11-15% of Ni, 10-14% of W, 2.4-4.3% of Mo, 1.2-1.6% of Al, 2.8-3.6% of Ti, 0.1-0.5% of Nb, 1.2-1.8% of Ta, 0.03-0.06% of Re, 0.01-0.05% of Ce, 0.02-0.1% of C, 0.005-0.015% of B, 0.02-0.07% of Zr and the balance of Co. The alloy preparation process route is vacuum melting-remelting-forging-hot rolling-drawing-solid solution treatment-aging treatment. Raw materials are compounded according to percentage by mass and then melted and re-melted; after that, forging and rolling are performed to obtain an alloy wire rod; multi-drawing is conducted to prepare an alloy wire of phi 0.06-0.4 mm; and finally, solid solution treatment and aging treatment are performed. Through reasonable ingredient control and adding of alloy elements, the alloy wire has high yield and excellent high-temperature wear resistance, high-temperature corrosion resistance, oxidation resistance and high strength. As a sealing brush wire material, the high-temperature oxidation resistant wearproof Co-based alloy wire has the advantages that the sealing effect can be effectively improved, and the service life is prolonged.

The invention discloses a hot rolling method of a metallurgical bonding wear-resistant composite tube, belonging to the field of tube rolling methods. The hot rolling method comprises the following steps of: producing a centrifugal blank of bearing steel with external low-carbon steel and internal high-carbon chromium by a centrifugal pouring technology; performing a perforation deformation operation or piercing constant-deformation operation, wherein a small elongation coefficient is adopted in the operation; and finally, performing a roll-piercing constant-deformation operation again to obtain a target composite tube, wherein a large elongation coefficient is adopted in the operation. The method disclosed by the invention adopts two deformation processes; the first perforation deformation operation or piercing constant-deformation operation improves the as-cast structure of the centrifugal blank, refines the crystal grains and improves the plasticity of the centrifugal blank; and the second piercing constant-deformation operation is used for producing a finished product of composite tube with the required specification. The method disclosed by the invention effectively avoids the defects of rolling crease, internal warp and the like on the inner wall in the production of a metallurgical bonding wear-resistant composite tube of bearing steel with external low-carbon steel and internal high-carbon chromium, and greatly improves the yield and economic benefits, wherein the yield reaches 90%.