32results about How to "High flex ratio" 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 relates to a method for preparing fine-grain dual-phase steel, in particular to preparing fine-grain dual-phase steel from low-carbon (manganese) steel. This method austenitizes ordinary low-carbon (manganese) steel, obtains a fine austenite structure through multi-pass deformation in the recrystallization zone, and supercools to a certain temperature range from A3 to Ar3 at an appropriate cooling rate. The temperature is subjected to multi-pass deformation, and the strain rate is between 0.1s-1 and 30s-1. By controlling the strain of each pass, 80% to 90% of the ferrite transformation value is obtained, and then rapidly cooled or quenched to room temperature. The average size of equiaxed ferrite grains in the fine-grained dual-phase structure obtained by the above process is less than 5 microns, the volume fraction of evenly distributed martensite islands is 10% to 15%, and the average size is less than 3 microns. The process is more controllable, the structure is more uniform, and it is easy to realize on the traditional hot rolling mill.

The invention discloses a high-tensile-to-yield-ratio common hot rolled steel plate and a making method thereof. The high-tensile-to-yielding-ratio common hot rolled steel plate comprises, by mass, 0.12-0.22% of C, 0.12-0.30% of Si, 0.30-0.90% of Mn, 0.025% or less of P, 0.025% or less of S, 0.0010-0.0020% of B, and the balance Fe and residual elements. The making method of the high-tensile-to-yielding-ratio common hot rolled steel plate comprises the steps of converter smelting, LF furnace refining, continuous casting, plate blank heating, rolling, controlled cooling and finishing. The making method of the high-tensile-to-yielding-ratio common hot rolled steel plate has a low production cost, changes very small chemical components of a common hot rolled steel plate and almost changes no microscopic structure of the common hot rolled steel plate. The addition of the boron element is very small, so the influence on the processing making cost of the common hot rolled steel plate is very small. The addition of 10-20ppm of the boron element to low carbon steel increases the tensile strength of steel by 5-15MPa and decreases the yield strength by 30-50MPa, so the tensile-to-yield ratio of the steel is substantially improved.

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.

A hot-rolled ribbed steel bar having a strength-to-yield ratio of 1.25 or more comprises 0.17-0.25wt% of C, 0.4-0.8wt% of Si, 1.2-1.5wt% of Mn, 0.045wt% or less of P, 0.045wt% or less of S, 0.05-0.08wt% of V, 0.006-0.018wt% of N, and the balance of Fe and impurity elements, and has a specification diameter of 12-40mm. A production method of the hot-rolled ribbed steel bar comprises the following steps: desulfurizing molten iron; carrying out top-bottom blowing of a converter; carrying out component fine-adjustment at an argon station, and blowing in nitrogen; refining an LF furnace, and blowing nitrogen into the LF furnace; continuously casting; carrying out stacking cooling; heating casted blanks; carrying out rough rolling and finish rolling; and naturally cooling to room temperature. Nitrogen is blown to realize greatly reduced cost, greatly reduced vanadium alloy consumption, increased V (C,N) amount and dispersity with the increase of the content of N in steel, substantial reinforcement effect and stable mechanical performances on the premise that mechanical performances comprising a hot-rolled yield strength of above 530MPa, a strength-to-yield ratio of 1.25-1.30, an A value of 18% or more and an Agt value of 10 or more are guaranteed.

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 invention relates to a reinforcing steel bar and a processing method thereof, in particular to a high-strength reinforcing steel bar with spiral fins and a processing method of the high-strength reinforcing steel bar. The high-strength reinforcing steel bar consists of following components including, in weight percentage, from 0.25 to 0.4% of C, from 0.1 to 0.2% of Si, from 0.3 to 0.45% of Mn, from 0.04 to 0.05% of Nb, from 0.08 to 0.09% of Cr, from 0.01 to 0.04% of V, from 0.002 to 0.003% of B, from 0.001 to 0.003% of Mo, from 0.015 to 0.03 of Al, from 0.002 to 0.003% of S, from 0.008 to0.009% of Ti, from 0.004 to 0.005% of Ni, from 3 to 5% of composite rear earth and the balance Fe. The processing method includes using a roll to roll a reinforcing steel bar into a reinforcing steelbar with the continuous spiral fins on the surface in a hot state; feeding the reinforcing steel bar with the continuous spiral fins on the surface after hot rolling into a heating furnace and heating the reinforcing steel bar to the temperature of 880-990 DEG C; then fast cooling the reinforcing steel bar to the temperature of 650-680 DEG C by an online cooling device via compressed air or vaporous quenching liquid; quenching in a quenching device by water or quenching liquid for 15-25 seconds; and tempering after heating the reinforcing steel bar to the temperature of 500-550 DEG C via a tempering heating furnace. The high-strength reinforcing steel bar with the spiral fins has a good anchoring property, fine ductility and a high yielding-to-tensile ratio.

The invention provides a HRB600E normal-speed hot-rolled ribbed steel bar with a yield ratio greater than 1.26 and a production method thereof. The production method of the HRB600E normal-speed hot-rolled ribbed steel bar with a yield ratio greater than 1.26 comprises the following steps: Process stage: blast furnace hot metal smelting, hot metal desulfurization pretreatment, converter molten steel smelting, LF refining, billet continuous casting, hot continuous rolling, cut-to-length cutting and inspection; the temperature control in hot continuous rolling is: control the casting slab heating temperature to 1150-1200°C, billet heating time 60-90 minutes, rolling start temperature 1020-1080°C. Normal speed hot-rolled ribbed steel bar adopts the above-mentioned production method.

The invention discloses a Nb, V composite 700MPa-grade high-strength anti-seismic reinforcement steel and a production method thereof, which belong to the technical field of hot-rolled ribbed reinforcement. Its chemical composition and mass percentage content include C: 0.25-0.35%, Si: 0.80-1.20%, Mn: 1.00-1.20%, V: 0.15-0.25%, Nb: 0.010-0.030%, Cr: 0.80-1.00% , N: 0.015~0.025%, P: ≤0.025%, S: ≤0.010%, the rest are Fe and unavoidable impurity elements; Nb, V composite microalloying, converter steelmaking (or electric arc furnace), continuous rod Rolling in steel rolling mills, under the existing technology and equipment level of steel enterprises, realizes large-scale industrial production of 700MPa high-strength seismic steel bars to meet the needs of high-rise and long-span concrete building structures in my country.

This invention relates to a aseismatic heat rolled steel bar with high strength, which belongs to alloy steel, especially to the heat rolled steel bar, the steel bar is composed by the following elements: 0.07-0.16%C, 1.2-2.0%Si, 1.5-2.0%Mn, <=0.4%Cr, 0.02-0.14%V, the rest is Fe and impurity. The universal steel-making device uses the universal technology; it smelts steel according to the said component range and produces heat rolled steel bar or rod with highe strength and better aseismatic charater. Wherein the yield strengthen sigmas(p0.2)>=550MPa, the yield proportion sigmab / sigmas(p0.2)>=1.45. And the high strength and high yield proportion of the steel bar can enforce the aseismatic charater of the building.

The invention provides an HRB600E ordinary-speed hot-rolled ribbed steel bar with the tensile-to-yield ratio larger than 1.26. A production method of the HRB600E ordinary-speed hot-rolled ribbed steel bar with the tensile-to-yield ratio larger than 1.26 comprises the following process stages which are conducted in sequence: blast furnace molten iron smelting, molten iron desulfurization pretreatment, converter molten steel smelting, LF refining, square billet continuous casting, hot continuous rolling, fixed-length shearing and inspection. The temperature control in the hot continuous rolling is as follows: the heating temperature of a casting blank is controlled to be 1150-1200 DEG C, the heating time of a steel billet is 60-90 minutes, and the initial rolling temperature is 1020-1080 DEG C. The production method is adopted for the ordinary-speed hot-rolled ribbed steel bar.