35results about How to "Guaranteed ferrite content" patented technology

The invention relates to a steel bar and its production process, which is a 630MPa grade high-strength hot-rolled steel bar and its production process. The chemical composition in weight percentage is: C: 0.38-0.43%, Cr: 0.8-1.1%, Mn: 0.75- 1.0%, Mo: 0.15-0.25%, Si: 0.15-0.3%, 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 630Mpa, 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 high-strength building steel bar of 600 MPa level and above and an application method thereof. : 0.6-1.3%, Mn: 0.4-0.8%, Cr: 0.6-0.7%, Mo: 0.12-0.28%, Ni: 0.3-0.55%, V: 0.2-0.3%, S: <0.05%, P: < 0.02%, the balance is Fe, (1) put the steel bar into the heating furnace for heating; (2) carry out preliminary hot rolling of the steel bar; (3) put the cooled steel bar into the tempering furnace and heat it to 500-550 °C; Steel bars are sprayed with high-pressure water or quenching liquid; (5) inspection and storage are carried out; the invention has strong bearing capacity, improves safety, reduces the number of steel bars used, and reduces costs.

The invention discloses a more than 630MPa level high strength steel bar comprising the following components: by weight, 0.28%-0.38% of carbon, 0-0.35% of silicon, 0-0.90% of manganese, 0.80%-1.50% of Cr, 3.00%-4.00% of nickel, 0.40%-0.60% of molybdenum, 0-0.015% of P, 0-0.015% of sulfur, 0-2.0ppm of hydrogen, 0.10%-0.20% of vanadium, 0-0.025% of titanium, 0-0.20% of copper, 0-0.05% of aluminum, 0-0.50% of residual elements and the balance of Fe; the invention also designs an application method of the more than 630MPa level high strength steel bar in reinforced concrete; and the more than 630MPa level high strength steel bar has the advantages of high strength, steel saving, no pollution, good hardenability, low tendency to crack and low relaxation degree.

The invention discloses a method for manufacturing prestressed steel wire coated with alloy coating. The method is carried out in the following steps: (1) Alloy coating is arranged, and the alloy coating is in powder form; (2) Prestressed steel wire is pickled sequentially with wire rod treatment, phosphating treatment and surface drying treatment; (3) send the treated prestressed steel wire into the wire drawing machine and draw it into the required specification and size, and then clean the prestressed steel wire; (4) send the prestressed steel wire into the thermal spraying equipment, and configure The good alloy powder is evenly sprayed on the surface of the prestressed steel wire with a spray gun, enters the intermediate frequency heating furnace, and heats the prestressed steel wire to 550-570°C within 5-8 seconds; (5) the prestressed steel wire enters the quenching cooling device, passes The second cooling process is cooled, and finally air-cooled to room temperature, then enters the wire take-up machine, inspects and puts into storage; thereby obtains the prestressed steel wire coated with alloy coating; the present invention increases the strength of the prestressed steel wire, and the wear resistance and resistance The corrosion resistance is further improved and the service life is increased.