The present invention belongs to the field of steel and iron materials. Disclosed are a steel wire rod for producing an alloy tool having a long fatigue life and high impact resistance, and the use thereof. The steel comprises the following chemical components, in percentages by weight: C: 0.83-0.92%, Si: 2.30-2.60%, Mn: 0.40-0.80%, Cr: 0.70-1.05%, Ni: 1.31-1.61%, V: 0.14-0.30%, Al: 0.025-0.060%, P≤0.025%, S≤0.020% and the balance of Fe and inevitable impurities. The alloy tool steel wire rod obtained in the present invention is suitable for manufacturing a screwdriver bit, a screwdriver, a hexagon wrench, etc., which have long fatigue life and the high impact resistance requirements, and has the following performance: a hardness of 60-62 HRC, a fatigue life of not lower than 30 thousand times, and an impact resistance of not lower than 60 seconds.
The present invention belongs to the technical field of metallurgy, and particularly relates to a method for improving homogeneity of a high-carbon steel small billet casting blank based on a brand-new reduction mode. The method comprises the following steps: during the casting process, starting crystallizer electromagnetic stirring and tail end electromagnetic stirring, wherein the tail end electromagnetic stirring corresponds to a casting blank center solid fraction fs = 0.1-0.2, and the pulling speed is controlled to be 1.6-3.0 m/min; carrying out soft reduction at the solidification tail end of the casting blank, wherein the soft reduction interval corresponds to a casting blank center solid fraction fs = 0.4-0.85 and a reduction amount of 8-16 mm, and distributing same to multiple rollers for small-amount and multi-roller continuous soft reduction operation; and carrying out single-roller heavy reduction on the first compression roller corresponding to the casting blank center solid fraction fs of 1. By means of the method of the present invention, not only is homogenization realized under the condition that high-efficiency production of a high-carbon steel small billet is ensured, thereby opening up a brand-new production process approach for producing a high-quality high-carbon steel casting blank in an energy-saving, low-consumption and low-cost manner, but an important foundation is also laid for producing a fire material high-quality high-carbon special steel from a small billet.
A low-carbon and energy-saving production method for a 2,060-MPa-grade-or-higher wire rod for a bridge cable. By means of the component design of 'high chromium/medium silicon/no precious metal alloy' combined with the technological processes of 'KR pretreatment→BOF converter→LF refining→RH vacuum degassing→continuous casting of a small square billet→billet finishing→billet heating→controlled rolling→new-type DP controlled cooling (air cooling and fog cooling), bloom cogging and heat treatments such as a water bath, a salt bath and a lead bath are not required. A microscopic structure with a high sorbitizing rate, a small cementite interlamellar spacing and a low network carbide level can still be obtained; and the finally prepared steel wire has a tensile strength of ≥2,060 MPa and a torsion index of ≥30 times, can be wound 8 or more times, and meets the construction requirements of national large-span and ultrahigh-strength cable ropes for bridge engineering. The process successfully replaces rolling via heating twice and off-line heat treatments, and has the advantages of low energy consumption cost, reduced carbon emissions, environmental friendliness, high production efficiency, etc.
A method for verifying accuracy of a secondary cooling solidification model, comprising the following steps: S1, establishing a secondary cooling solidification model on line by utilizing Primetal; S2, obtaining a casting blank under a continuous casting production technology, and calculating a central solid fraction fs of the casting blank entering a withdrawal and straightening machine; S3, using the withdrawal and straightening machine for slight pressing, and starting single-roller or multi-roller pressing in a region when the central solid fraction fs ranges from 10% to 50%; and S4, after the casting blank is sampled, detecting initial positions of cracks by means of longitudinal low-magnification acid pickling, and comparing X obtained by means of measurement according to the actually-measured initial position of the crack with the casting blank thickness D simulated by the secondary cooling solidification model. The accuracy of the secondary cooling solidification model can be verified in a general pressing process crack generation manner, generating cracks in the casting blank in a longitudinal low-magnification manner can be guaranteed, and the accuracy of the secondary cooling solidification model is verified according to the initial positions of the cracks.
The present invention belongs to the technical field of metallurgy, and specifically relates to a control method for a medium-carbon high-manganese vanadium-containing alloy structural round steel material structure. In a continuous casting process, a low superheat degree and slow pulling speed pouring are used, a pulse magnetic oscillation solidification homogenization technology is used, and in addition, a large electromagnetic stirring current is used for smashing dendritic crystals, so as to increase a nucleation core of the dendritic crystals, expand an isometric crystal area and reduce a columnar crystal area, and therefore casting blank segregation is reduced, wherein the electromagnetic stirring current of a crystallizer is 350 A, and the electromagnetic stirring current at the end is 450 A. In a rolling process, a high-temperature long-time diffusion heating process is used, and a controlled rolling and controlled cooling process is used. The resulting medium-carbon high-manganese vanadium-containing alloy structural round steel material has a uniform structure, and the proportion in area of a heat affected zone (abnormal structure) after user friction welding machining is reduced to 5% or below, which reaches the international advanced level.
2322233 control range is 1.3-2.5, the refining slag addition amount is 8-10 kg/t, and meanwhile, the final slag FeO+MnO is required to be smaller than 0.8%. A steel ladle molten pool and a ladle bottom are made of aluminum carbon, a middle ladle is made of an alumina dry material, and a stopper is made of integral aluminum carbon. According to the present invention, the reaction between molten steel and refractory material can be reduced while the slag steel reaction is inhibited, the generation of spinel inclusions is reduced, and the continuous casting heats and the qualification rate of water immersion flaw detection are remarkably improved.
A cooling roller way for improving the cooling uniformity of a spinning coil and a usage method. The cooling roller way comprises a roller way body (1) and several guiding mechanisms (2) installed on two sides of the roller way body (1), the guiding mechanisms (2) at two sides of the roller way body (1) being staggered. The roller way body (1) is used to transport a coil (3), and the guiding mechanisms (2) are used to change the running trajectory of the coil (3), so that overlapping points (31) of the coil (3) are uniformly distributed.
B21B 45/02 - Devices for surface treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
8.
METHOD FOR PRODUCING FREE-CUTTING STEEL HOT-ROLLED WIRE ROD FOR OA SHAFT
The present invention pertains to the technical field of ferrous metallurgy, and relates to a method for producing a free-cutting steel hot-rolled wire rod for an OA shaft. According to the present invention, appropriate chemical components have been designed so as to ensure that a wire rod met machinability and mechanical property requirements. Process conditions of converter-based smelting, LF furnace-based refining, continuous casting machine-based continuous casting, billet rolling, billet finishing, rolling of finished wire rods, and wire rod packaging and protection are defined. For example, conditions in a rolling process are defined, such as a heating temperature, a heating time, a finishing rolling temperature, a sizing temperature, a spinning temperature, a cooling process, etc., such that the produced free-cutting steel hot-rolled wire rod for the OA shaft has chemical components that conform to standards, good surface quality, excellent machinability, and good product stability, and meets requirements of a downstream user in terms of machinability and surface quality stability. Therefore, eventual OA shaft products such as printer shafts, copier shafts, fax machine shafts, camera shafts, and the like acquired by means of machining have good stability, and meet requirements for flaw detection.
Disclosed are a preparation method for steel for an engineering machinery gear and a preparation method for a forge piece. By combining adjustment and optimization of processes such as converter smelting, LF furnace refining, RH vacuum treatment, continuous casting, and rolling, 0.38-0.43% of C, 0.17-0.37% of Si, 0.60-0.80% of Mn, 1.10-1.20% of Cr, 0.020-0.040% of Al, no more than 0.025% of P, 0.020-0.035% of S, 0.15-0.25% of Mo, no more than 0.20% of Cu, 60-150 ppm of N, and 0.015-0.035% of Nb in steel are controlled, the purity of molten steel is improved, the components and structure of the material are uniform, and finally, the comprehensive performance of the material is greatly improved.
B22D 11/115 - Treating the molten metal by using agitating or vibrating means by using magnetic fields
C21D 8/06 - Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
C21D 1/18 - HardeningQuenching with or without subsequent tempering
C21D 9/32 - Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articlesFurnaces therefor for gear wheels, worm wheels, or the like
10.
CONTROL METHOD FOR SEGREGATION AND NET CARBIDE OF 86-GRADE HIGH-STRENGTH CORD STEEL WIRE ROD
Disclosed in the present invention is a control method for segregation and net carbide of an 86-grade high-strength cord steel wire rod. The control method comprises: KR molten iron pre-desulfurization, BOF converter smelting, LF furnace refining, continuous casting CC, casting blank surface treatment, casting blank heating, controlled rolling and controlled cooling procedures which are carried out in sequence. The 86-grade high-strength cord steel wire rod comprises the following components in percentage by weight: C: 0.85-0.90%; Si: 0.15-0.35%; Mn: 0.40-0.60%; P: ≤ 0.015%; S: ≤ 0.010%; Cr: ≤ 0.010%; Al: ≤ 0.005%; and the balance of Fe. According to the present invention, the segregation and net carbide of a wire rod are mitigated by combining continuous casting of small square billets with wire rolling, the period and cost are greatly reduced, the sorbitizing rate of the manufactured φ5.5mm wire rod is greater than or equal to 90%, the center segregation of the wire rod is slight, no net-shaped cementite exists in the center, and the drawing use requirements of users are satisfied.
2232222-MgO-based inclusions. Such inclusions are deformed uniformly and sufficiently during hot rolling, and the width of the inclusions in the final wire rod can be controlled to be 2 microns or less. In addition, the erosion of the refining slag into a ladle refractory material can be reduced, and the ladle age can be increased by twofold or more.
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