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

The invention discloses a production method for a thermal treatment prestressed steel strand. According to the production method for the thermal treatment prestressed steel strand, AISI4340MOD steel is selected as raw materials and theAISI4340MOD steel comprises the following componentsby mass percent, 0.3 to 0.32 % of carbon, 0.18 to 0.36 % of silicon, 0.50 to 0.70 % of manganese, 0.90 to 1.10 % of chromium, 0.20 to 0.30 % of molybdenum, 0 to 0.02 % of phosphorus, 0 to 0.025 % of sulfur, 0 to 1.8 ppm of hydrogen, 0 to 0.40 % of nickel, 0 to 0.03 % of vanadium, 0 to 0.30 % of copper, 0 to 0.9 % of residual elements and the remaining is ferrum. The production method for the thermal treatment prestressed steel strand has the advantages of improving the strength and hardenability of the steel strand, enabling the steel strand to be not easy to craze, low in looseness, uniform and smooth in surficial galvanization.

The present invention discloses a chromium-molybdenum low-alloy prestress aluminum-cladding steel wire manufacturing method, wherein the chromium-nickel-molybdenum alloy structure steel is adopted as a billet material and comprises, by mass, 0.28-0.38% of carbon, 0-0.35% of silicon, 0-0.90% of manganese, 0.80-1.50% of chromium, 3.00-4.00% of nickel, 0.40-0.60% of molybdenum, 0-0.015%of phosphorus, 0-0.015% of sulfur, 0-2.0 ppm 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. According to the chromium-molybdenum low-alloy prestress aluminum-cladding steel wire manufacturing method designed by the present invention, strength and toughness of the steel wire can be substantially increased, a corrosion resistance degree of the steel wire can be enhanced, and a service life can be prolonged.

The invention discloses a processing method for a chrome molybdenum low alloy prestressed steel reinforcement connection joint. Chrome-nickel-molybdenum low alloy structural steel serves as a blank, the percentage by weight of nickel is controlled to range from 3.00% to 4.00%, and the percentage by weight of chrome is controlled to range from 0.80% to 1.50%; through hydrogen diffusion heat treatment, under the premise that the hydrogen content of the blank is lower than 2.0 ppm, the hydrogen content is further reduced, the situation that white point cracks of the blank and heat treatment stress induce hydrogen induced cracks and hydrogen induced delay cracks is avoided, the toughness, elasticity, abrasive resistance and impact resistance of the steel are improved, and the steel is compact. Through the processing method for the chrome molybdenum low alloy prestressed steel reinforcement connection joint, the strength, toughness and tension stress of the steel reinforcement connection joint can be greatly improved, the corrosion resistance of the steel reinforcement connection joint can be enhanced, and the service life of the steel reinforcement connection joint can be prolonged.

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 relates to a urea-class stainless steel pipe and a production process thereof. The urea-class stainless steel pipe comprises the following chemical components: 19.6 to 19.8 percent of Ni, 3.2 to 3.5 percent of Mo, 19.1 to 19.3 percent of Cr, 0.025 to 0.028 percent of C, 1.3 to 1.5 percent of Si, 1.7 to 1.9 percent of Mn, 0.03 to 0.05 percent of S, 0.035 to 0.037 percent of P, 0.03 to 0.05 percent of Cu, 0.012 to 0.016 percent of Co, 0.03 to 0.05 percent of O, 0.3 to 0.5 percent of Al, 0.07 to 0.09 percent of Nb, 0.001 to 0.003 percent of B, 0.03 to 0.05 percent of N and the balance of Fe. Due to two different procedures of heating and cooling, the steel pipe has excellent intercrystalline corrosion resistance and selective corrosion performance and has excellent strong plasticity.

The present invention discloses a chromium-molybdenum low-alloy prestress aluminum-cladding steel wire manufacturing method, wherein the chromium-nickel-molybdenum alloy structure steel is adopted as a billet material and comprises, by mass, 0.28-0.38% of carbon, 0-0.35% of silicon, 0-0.90% of manganese, 0.80-1.50% of chromium, 3.00-4.00% of nickel, 0.40-0.60% of molybdenum, 0-0.015%of phosphorus, 0-0.015% of sulfur, 0-2.0 ppm 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. According to the chromium-molybdenum low-alloy prestress aluminum-cladding steel wire manufacturing method designed by the present invention, strength and toughness of the steel wire can be substantially increased, a corrosion resistance degree of the steel wire can be enhanced, and a service life can be prolonged.

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.

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 manufacturing method of a high-yield non-bonding prestress steel bar. The steel bar has the advantages of bringing convenience to manual construction, being low in cost, high in strength, good in ductility and high in delayed fracture and saving steel, has ideal insulation effects, and can reduce environment pollution. According to the manufacturing method, steel structure anticorrosive paint is adopted, good mechanical performance and excellent anti-corrosion performance are achieved, stability for weather, oil water mixtures and the like is good, various colors can be mixed according to needs, the steel bar can have good visual effects after the steel anticorrosive paint is used, attractiveness and elegance in decoration are achieved, and cost can also be saved due to the fact that the paint has long anti-corrosion time.

The invention relates to a steel bar and its production process, which is a 730MPa grade high-strength hot-rolled steel bar and its production process. The chemical composition in weight percentage is: C: 0.48-0.53%, 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 730Mpa, 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 present invention discloses a AISI4340 prestress steel bar manufacturing method, wherein a AISI4340MOD steel is adopted as a billet material, the billet material is subjected to smelting and finish rolling to obtain a prestress steel bar forging stock with the required size, the prestress steel bar forging stock is sequentially subjected to a hydrogen diffusion heat treatment, rough processing, water cooling quenching and air cooling quenching, a polyethylene corrosion resistance coating is coated on the outer surface of the steel bar forging stock, and a polyethylene heat shrink sleeve is arranged outside the polyethylene corrosion resistance coating. According to the AISI4340 prestress steel bar manufacturing method designed by the present invention, the obtained AISI4340 prestress steel bar has characteristics of high strength, good ductility, strong delayed fracture resistance, steel saving, low relaxation, easy welding, good upsetting property and the like, and further has effects of substantially enhanced corrosion resistance sealing property, and effectively improved mechanical strength.

The invention discloses a midair multipoint vertical steel bar connecting joint which is made of number 45 round steel. The round steel comprises the chemical components, by weight, 0.38-0.43% of C, 0.8-1.1% of Cr, 0.75-1.0% of Mn, 0.15-0.25% of Mo, 0.15-0.3% of Si, 0.035% of S, 0.035% of P, 0.035% of N, and the balance Fe. The invention further discloses a construction method of the midair multipoint vertical steel bar connecting joint. The midair multipoint vertical steel bar connecting joint and the construction method thereof are simple and practical, simple in construction and capable of greatly improving the strength, the toughness and the tension stress of the steel bar connecting joint.

The invention discloses a production method for a thermal treatment prestressed steel strand. According to the production method for the thermal treatment prestressed steel strand, AISI4340MOD steel is selected as raw materials and theAISI4340MOD steel comprises the following componentsby mass percent, 0.3 to 0.32 % of carbon, 0.18 to 0.36 % of silicon, 0.50 to 0.70 % of manganese, 0.90 to 1.10 % of chromium, 0.20 to 0.30 % of molybdenum, 0 to 0.02 % of phosphorus, 0 to 0.025 % of sulfur, 0 to 1.8 ppm of hydrogen, 0 to 0.40 % of nickel, 0 to 0.03 % of vanadium, 0 to 0.30 % of copper, 0 to 0.9 % of residual elements and the remaining is ferrum. The production method for the thermal treatment prestressed steel strand has the advantages of improving the strength and hardenability of the steel strand, enabling the steel strand to be not easy to craze, low in looseness, uniform and smooth in surficial galvanization.

The invention discloses a processing method of an above-600MPa-grade high-strength steel bar connection sleeve. The sleeve selects No.45 round steel as a raw material, and the No.45 round steel comprises 0.38-0.43wt% of C, 0.8-1.1wt% of Cr, 0.75-1.0wt% of Mn, 0.15-0.25wt% of Mo, 0.15-0.3wt% of Si, below 0.035% of S, below 0.035wt% of P, below 0.035wt% of N, and the balance Fe. The designed processing method of the above-600MPa-grade high-strength steel bar connection sleeve substantially improves the tensile strength and the elongation rate, guarantees the external diameter dimension and fineness of a steel tube, and reduces the friction stress between a tap and the inner wall of the sleeve.

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.

The invention discloses a method for manufacturing a prestress steel strand coated with nichrome powder. The method for manufacturing the prestress steel strand coated with the nichrome powder comprises the following steps that (1) the nichrome powder comprises, by weight, 0.5-3.2% of Re, 48-54% of Ni, 18-32% of Cr, 1.6-5.5% of Si, 0.3-0.8% of S, 0.5-2.2% of C, 10-16% of Fe, 1.2-10% of Mn, and 1-2.5% of composite rear earth; (2) a plurality of wire rod steel wires are fed into a heating furnace; (3) the nichrome powder is evenly sprayed on the surfaces of the wire rod steel wires through a spray gun; (4) the wire rod steel wires are stranded through a stranding machine to form the steel strand which is of a steel wire rope shape; (5) the steel strand enters a quenching device; (6) the nichrome powder is evenly sprayed on the surface of the steel strand again through the spray gun; (7) the steel strand enters a layer winder to be packaged. According to the method for manufacturing the prestress steel strand coated with the nichrome powder, the strength, wear resistance and corrosion resistance of the steel strand are improved.