57results about How to "Improve atomic activity" patented technology

The invention relates to a steel bar and its production process, which is a 830MPa grade high-strength hot-rolled steel bar and its production process. The chemical composition in weight percentage is: C: 0.38-0.43%, Cr: 0.7-0.9%, Mn: 0.6- 0.8%, Mo: 0.15-0.25%, Si: 0.2-0.3%, Ni: 1.6-2%, S: <0.035%, P: <0.035%, N: <0.035%, and the balance is Fe. The steel bar yield strength of the present invention can reach 830MPa, has the advantages of high strength, good ductility, strong hysteresis fracture resistance, steel saving, low relaxation, easy welding, good upsetting performance, etc., and can fully dissolve carbides and evenly diffuse, It avoids the precipitation of carbides between grains and causes excessive intergranular corrosion and pitting corrosion.

The invention discloses a steel bar for high-strength prestressed concrete, the chemical composition of which is: C: 0.20-0.25%, Si: 1.50-1.85%, Mn: 0.20-0.50%, Cr: 0.07-0.09%, Mo: 0.30‑0.35%, V: 0.25‑0.35%, Nb: 0.05‑0.08%, Ti: 0.42‑0.61%, Ni: 0.15‑0.25%, Ca: 0.25‑0.40%, S≤0.025%, P≤0.025 %, Cu≤0.20%, compound rare earth: 0.15-0.30%, and the balance is Fe; the present invention also designs a production process of steel rods for high-strength prestressed concrete as follows: smelting to obtain steel billet-rolling-cooling treatment-the first Secondary rolling - heat treatment and stabilization treatment - gas nitriding treatment - spinning and coiling - bundling and storage.

The invention discloses a machining tool for a spherical plate. The tool comprises an upper mold and a lower mold, wherein the lower mold comprises a lower columnar structure defined through welding connection of sides of at least three lower rib plates and a seat plate arranged at the bottom of the lower columnar structure; a machining concave end surface is arranged at the top of the lower columnar structure, and the curve of the machining concave end surface is consistent with the radian of a curved surface of the to-be-machined spherical plate; the upper mold comprises an upper columnar structure defined through welding connection of sides of at least three upper rib plates and a top plate arranged at the top of the upper columnar structure; and a machining convex end surface is arranged at the lower end of the upper columnar structure and is matched with the machining concave end surface in radian. The smooth degree of the appearance of the plate can be guaranteed with the tool, assembly, electric welding and polishing in following processes can be reduced, the manufacturing period of the spherical plate can be shortened, and the manufacturing cost of the spherical plate can be saved.