46results about How to "High strength level" patented technology

The present invention is heat treatment process of high-strength finish-rolled spiral steel bar. The finish-rolled spiral steel bar in rotary state is fed from the feeding system of the continuous heat treatment apparatus to the roller conveyer at the speed of 2-6 m / min, heated to 800-1000 deg.c in one induction heater, quenched in the cooler at temperature lower than 300 deg.c, and tempered in one other induction heater at 500-700 deg.c to produce finish-rolled spiral steel bar of higher strength grade. The finish-rolled spiral steel bar through said heat treatment process has obviously raised mechanical performance, thick hardened layer, fined crystal grains, stable performance, high strength and high toughness.

The invention belongs to the field of metal materials and discloses a large-thickness and high-strength quenched and tempered steel plate and a production method thereof. The steel plate mainly consists of the following chemical components by weight percentages: not more than 0.18% of C, 0.1-0.4% of Si, not more than 1.2% of Mn, 0.7-1.7% of Ni, 1.0-1.5% of Cr, 0.4-0.6% of Mo, 0.03-0.08% of V, 0.02-0.04% of Al, 0.0005-0.0020% of B, Fe and unavoidable impurities. The molten steel designed according to the components of the invention can be rolled into the large-thickness steel plate by smeltingprocess, casting process, heating process, rolling process, water cooling process and quenching and tempering process. The steel plate has the advantages of reasonable component design, good comprehensive properties and low production cost, can be applied to off-shore oil production platform engineering, power stations, engineering scaffolds and other industries and has good application prospect.

The invention discloses a structure steel plate for a bridge with the yield strength being 690MPa and a production method thereof. The structure steel plate comprises the following components in percent by weight: 0.040 percent to 0.080 percent of C, 0.20 percent to 0.25 percent of Si, 1.50 percent to 1.65 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.005 percent of S, 0.040 percent to 0.050 percent of Nb, 0.006 percent to 0.018 percent of Ti, 0.25 percent to 0.35 percent of Cr, 0.25 percent to 0.30 percent of Mo, 0.30 percent to 0.40 percent of Cu, 0.20 percent to 0.30 percent of Ni and the balance of Fe and unavoidable impurities, the sensitive composition of welding cracks meets the formula Pcm is less than or equal to 0.22, the carbon equivalent CEV is less than or equal to 0.50, 10C plus 4Cr plus Cu equals to 6.5 to 7.5. The structure steel plate designed and produced by the process has good toughness; the yield strength Rel is more than or equal to 690MPa, the tensile strength Rm is more than or equal to 770MPa, the elongation A is more than or equal to 18 percent, and -40 DEG C low-temperature impacting performance is more than or equal to 100J. Compared with the existing bridge steel technology, the structure steel plate disclosed by the invention has the advantages that the strength level is greatly improved; in addition, the welding performance of the steel plate is improved by strictly controlling the carbon equivalent CEV to be less than or equal to 0.50 and Pcm to be less than or equal to 0.22.

The invention discloses a microalloy HRB500E steel bar containing chrome and nitrogen and a production method thereof. By fully utilizing the strengthening effect and the corrosion-proof effect of chrome on the steel bar, solid solution strengthening elements, namely manganese and silicon, are partially substituted, and a microalloy element, namely vanadium or columbium is partially or fully substituted; a cheap nitrogen element is used for performing microalloy treatment on the steel bar, so that the micro nitrogen separating strengthening effect is achieved; by the production method, the HRB500E steel bar can be produced; Rel of the steel bar is 520 to 580MPa, Rm of the steel bar is 640 to 730 MPa, A is 22 to 32 percent, Rm / Rel is 1.30 to 1.40, the cold bending qualified rate is 100 percent, the welding carbon equivalent weight is less than or equal to 0.50, and the comprehensive cost of one ton of steel bar is 40-100 yuan lower than that of one ton of the steel bar produced by the conventional method; during aging of three months, the fluctuation values of the Rm value and the Rel value are less than 10MPa; and the steel bar has excellent welding performance and good corrosion-proof property.

The invention discloses high-strength and anti-corrosion stainless steel. The high-strength and anti-corrosion stainless steel comprises chemical elements including, by mass percent, smaller than or equal to 0.1% of C, 0.1%-0.5% of Si, 0.1%-5% of Mn, 21.0%-23.5% of Cr, 21.5%-25.5% of Ni, 0.1%-5% of Mo, 0.01%-0.10% of Al, 0.01%-2.00% of W, 0.05%-0.10% of RE, 0.01%-0.3% of N, larger than 0% and smaller than or equal to 4.0% of Cu, larger than 0% and smaller than or equal to 2.0% of Co, and the balance Fe and other inevitable impurities. The high-strength and anti-corrosion stainless steel has good H2S and CO2 corrosion resisting performance and acidizing fluid corrosion resisting performance.

The invention relates to a method for producing the cold-formed steel of a U-shaped davit arm. The method comprises the following steps of: leading strong-strength sheet steel or a strong-strength steel coil into a roll for first formation, wherein the strong-strength sheet steel or the strong-strength steel coil is formed totally for 3 to 6 times; between the first formation and second formation, arranging induction heating equipment, and while forming profile steel, performing induction heating and stretching and straightening the sheet steel by utilizing roll speed differences produced by different roll diameters in the formation of each time by using the induction heating equipment; actually measuring the actual temperature of the sheet steel in the formation of each subsequent time in field according to sheet steel feeding velocity v, and controlling the temperature in an additional heating way; and performing subsequent operation such as cooling and shearing until strong-strength semicircular large-radius profile steel meeting target requirements is formed. The processes of induction heating, synchronous stretching and straightening of the roll, and the like are introduced into the conventional cold forming process, so that the low cost and high efficiency of the cold-formed steel and the characteristics of weak forming force, optimized size and the like of heat-formed sheet steel are integrated.