4 results about "Lath" patented technology

This invention discloses a method for producing easily formable ultra-high strength steel plates for engineering machinery, belonging to the field of metal material processing technology. This invention employs a medium-carbon + multi-element microalloying system, and through converter steelmaking + refining, continuous casting, billet heating, two-stage controlled rolling, and quenching + tempering heat treatment, produces ultra-high strength steel plates with a thickness of 5-20 mm. The resulting steel plate has a matrix structure of ultra-fine-grained lath martensite with an effective grain boundary size of 1.2-1.5 μm, a yield strength ≥1500 MPa, a tensile strength ≥1800 MPa, an elongation >10%, an impact energy >50 J at -40℃, and meets the requirements of D=6a and 180° bending without cracking. It possesses ultra-high strength, excellent low-temperature toughness, and cold formability, and can be directly used for forming key load-bearing structural components of engineering machinery. The process is simple and highly adaptable to industrial applications.

The utility model provides a kind of special-shaped corner shear wall construction formwork device, it includes several formwork components, opposite bolt, joint gap anti-overflow piece and corner connecting piece, the opposite bolt is used to connect the two groups of formwork components oppositely arranged;The joint gap anti-overflow piece is arranged on the opposite side of two groups of formwork components, to block the joint gap of adjacent formwork components on the same side;The corner connecting piece is arranged on the side of two groups of formwork components, to connect the steel pipe back lath in adjacent formwork components on the same side.The utility model can efficiently assemble and disassemble formwork device and guarantee the fastening effect of special-shaped corner formwork joint gap, improve construction efficiency and construction quality.

This invention relates to a heat treatment process for large-diameter 17-4PH thin-walled short rings with diameters of 800mm to 1300mm, wall thicknesses of 20mm to 40mm, and lengths ≤800mm. After forging, controlled-temperature cooling promotes partial microstructural transformation and prevents grain regeneration in the thin-walled short rings. Solution annealing ensures uniform and refined microstructure and grain size in the forged billet. After solution annealing, high-temperature tempering and slow, rate-limited cooling in the furnace to a certain temperature removes structural stress, diffuses hydrogen, and softens the billet hardness, facilitating subsequent rough machining. High-temperature solution cooling employs a combination of pre-cooling, oil cooling, and air cooling to minimize thermal and structural stress, preventing cracking of the thin-walled short rings and ensuring complete microstructural transformation to obtain fine lath martensite. During solution removal from the furnace, slow hoisting prevents deformation of the large-diameter 17-4PH thin-walled short rings due to their own weight. The produced large-diameter 17-4PH thin-walled short rings exhibit uniform overall quality, are free of cracks, and have low ellipticity after heat treatment.

The application relates to a heat treatment process for improving the grain size of Cr16Ni6 stainless steel, wherein the grain size is obviously improved to 4-6 levels after the heat treatment, and the product quality is improved; the process scheme is as follows: after forging, cooling treatment, one-time strengthening treatment, one-time tempering, two-time strengthening treatment and two-time tempering; the grain size is effectively improved; the forging organization is stabilized and part of the martensite organization is transformed through the after-forging cooling treatment, internal stress is reduced, and workpiece cracking is avoided; through the after-forging cooling treatment and the strengthening treatment, austenite is repeatedly transformed into fine lath martensite, nucleation is ensured in the subsequent high-temperature heating process, nucleation rate is increased, grain size is refined, and the grain size is improved from the original coarse 1-3 levels to the fine 4-6 levels.