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

The invention discloses pipeline steel with good and stable low-temperature flexibility and a method for rolling hot rolled coils thereof. The pipeline steel comprises the following compositions in percentage by weight: 0.03 to 0.070 percent of carbon, 0.19 to 0.30 percent of silicon, 1.50 to 1.90 percent of manganese, 0.010 to 0.020 percent of titanium, 0.015 to 0.040 percent of aluminum, less than or equal to 0.30 percent of nickel, less than or equal to 0.02 percent of chromium, less than or equal to 0.0002 percent of boron, less than or equal to 0.018 percent of phosphorus, less than or equal to 0.005 percent of sulfur, 0.002 to 0.003 percent of calcium, 0.20 to 0.40 percent of molybdenum, less than or equal to 0.30 percent of copper, 0.02 to 0.10 percent of niobium, less than or equal to 0.006 percent of nitrogen, less than or equal to 0.004 percent of oxygen, less than or equal to 0.00025 percent of hydrogen, and the balance of iron and impurities. The manufactured pipeline steel has the characteristics that sigma s is equal to be between 565 and 580 MPa; sigma b is equal to be between 665 and 690 MPa; and sigma s/sigma b is less than or equal to 0.85.

The invention relates to a gas shield welding wire with high strength and tenacity, which is suitable for the welding of 800MPa-grade high-strength steel. The gas shield welding wire comprises the following ingredients in percentage by weight: 0.02-0.05 percent of C, 0.30-0.80 percent of SiO, 2.0-2.50 percent of Mn, less than 0.010 percent of P, less than 0.010 percent of S, 0.70-1.2 percent of Cr, 0.70-1.2 percent of Mo, 0.02-0.12 percent of Ti, 0.003-0.005 percent of B, 2.0-3.2 percent of Ni, 0.05-0.1 percent of RE, 0-0.06 percent of Nb, and the balance of Fe and unavoidable impurities. The welding wire has the advantages of simple ingredient design, low cost, good manufacturability, and the like; in addition, and weld metal has high tenacity and is suitable for the welding at the position with higher low-temperature tenacity requirement. Experiments show that the Rm of the weld metal welded by the welding wire is not less than 800MPa, and the ReL is more than 760MPa; and the impact energy at -50 DEG C of the weld metal is not less than 37J.

The invention relates to a manufacturing process of a high-strength bolt resisting stress relaxation. The manufacturing process sequentially comprises working procedures of quenching and tempering, drawing, cold upsetting thread billet inner diameter/rod part/hexagon head, thread rolling, stabilizing, surface treatment and peening or round corner rolling strengthening and defect detection. In the quenching and tempering working procedure, wire rod strength is finally controlled at 85-65% of a finished product; in the drawing working procedure, the drawing deformation is controlled at 15-40%, in the stabilizing working procedure, the heating temperature is 200-450 DEG C, the temperature is kept for 0.5-4h and the bolt is taken from the furnace for air cooling. The high-strength bolt resisting stress relaxation has the beneficial effects of being adapted to the development of machinery industry, especially automobile industry, solving a deformation problem of a long bolt in quenching treatment, further improving the performance of resisting stress relaxation during practical use, and being capable of further increasing the strength of the bolt up to 1300MPa.

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 kind of niobium-titanium microalloying HRB400-scale screw-thread steel and a manufacturing method thereof. The screw-thread steel comprises C, Si, Mn, P, S, Nb, Ti, N and the balance Fe and impurities. The manufacturing method of the niobium-titanium microalloying HRB400-scale screw-thread steel comprises the following steps of smelting in a revolving furnace, treatment outside the furnace, continuous casting, casting blank heating and rolling. During smelting in the revolving furnace, alloy such as silicomanganese and ferroniobium is added for niobium microalloying treatment. During treatment outside the furnace, argon is blown in an argon station, and refining is conducted in an LF furnace. In the process of refining in the LF furnace, a ferrotitanium core-spun yarn is fed for titanium microalloying treatment. According to the technical scheme, before tapping, alloy such as silicomanganese and ferroniobium is added for niobium microalloying treatment, the ferrotitanium core-spun yarn is fed in the process of refining in the LF furnace for titanium microalloying treatment, after titanium is fused into molten steel, proper niobium-titanium microalloying treatment is conducted, the yield of the niobium-titanium alloy is increased, and stable, sustainable and low-cost production of the screw-thread steel is achieved.

The invention discloses thin-specification low-yield-ratio high-strength bridge steel and a production method thereof. A steel plate adopts a component design of increasing Mn and Cr and reducing Nb and Ti, and chemical components include, by mass, C: 0.06-0.08%, Si: 0.15-0.25%, P: less than or equal to 0.015%, S: less than or equal to 0.008%, Ni: 0.2-0.4%, Mo: 0.1-0.2%, Al: 0.01-0.045%, Mn+Cr: 1.90-2.20%, Nb+Ti: 0.035-0.05% and the balance Fe and other inevitable impurities. By means of a rolling and cooling process of high-temperature finish rolling and after-rolling variable-speed cooling,a ferrite+bainite bidirectional tissue is acquired, and the steel plate has a yield strength 520-570 MPa, a tensile strength 670-760 MPa and a yield ratio 0.69-0.79, and realizes a good balance of a thickness 8-16 mm, a bridge steel strength 500-550 MPa and a yield ratio.

A tear away diaper fastening system including a segment of loop material having a plurality of outwardly projecting loop elements adapted to engage cooperating hooking elements in juxtaposed contacting relation. The loop material includes a composite sheet of stitch bonded construction including a polymer film substrate layer. A first plurality of yarn elements extends in stitched relation through the substrate layer to define a plurality of parallel stitch lines of flat stitches extending along the machine direction of the sheet material to form a ground layer substantially covering an upper surface of the substrate layer. A second plurality of yarn elements extends in stitched relation through the substrate layer in zigzag crossing relation between parallel needle lines to define a plurality of raised loops extending above the ground layer.

The invention provided a niobium-nitrogen-containing micro-alloyed HRB 400 E steel bar and a production method thereof. The method is characterized in that the precipitation strengthening effect of niobium and nitrogen on the steel bar is utilized, parts of solid solution strengthening element manganese and silicon are replaced, parts or all of micro-alloyed element vanadium are replaced, and meanwhile, microalloying treatment is carried out on the steel bar by means of cheap nitrogen element, and the precipitation strengthening effect of the micro niobium and nitrogen are exerted. The steel bar is characterized in that Rel is 435-490 MPa, Rm is 590-650 MPa, A is 24%-35%, Rm/Rel 1.30-1.42, A<gt> is 11.5%-19%, the cold bending yield is 100%, and Ceq is less than or equal to 0.48%. Accordingto the steel bar and the method, the production cost is reduced by 30-80 yuan/ton compared with the production cost of a traditional method, three-month natural aging is performed, the fluctuation value of Rel and Rm is less than 10 MPa, the welding performance is good, and meanwhile, the performance index of the obtained steel bar is far more than GB/T 1499.2-2018 standard requirement.

The invention discloses a high service strength enameled steel plate and a preparation method thereof. The steel plate is prepared from the following chemical components in percent by weight: 0.1-0.15% of C, 0.3-0.5% of Si, 1-1.8% of Mn, less than 0.013% of P, less than 0.005% of S, 0.020-0.050% of Alt, 0.04-0.07% of V, 0.011-0.015% of N and the balance ferrum and impurities. The preparation method comprises the following steps: 1) carrying out pre-treatment, converter steelmaking and refining on molten iron to obtain casting blank molten iron; 2) continuously casting the molten iron to prepare a casting blank; 3) heating the casting blank; 4) carrying out multi-pass rough rolling and finish rolling to obtain a finish rolled plate; and 5) carrying out laminar cooling to coil to obtain a finished product. The yield strength of the steel plate is 460-550 MPa, the yield strength of the enameled steel plate is 400-460 MPa, and the enameled steel plate can be used for manufacturing a lowertank wall of an enameled spliced tank, the moisture storage capacity of which is greater than 9000 m<3>.

The support members of an X-style stand are separate from the brace assembly, and are assembled therewith by telescopic interengagement of at least one sleeve piece on the support member with the end portion of a leg of the brace, the sleeve piece being affixed to the support member with weldments that extend parallel to the longitudinal axis of the member. The sleeve pieces are fastened to the brace legs by elongate fasteners that extend through aligned apertures, which are also oriented parallel to the axis of the crosspiece. The disassembled stand is contained in a package that is of substantially reduced volume, as compared to the space required to contain an equivalent stand of conventionally welded construction.