249results about How to "High yield ratio" patented technology

A high-strength hot-dip galvanized steel sheet excellent in workability according to the present invention: contains C, Si, Mn and other elements; has a dual phase structure containing ferrite and martensite as the metallographic structure; and, in the ferrite structure, satisfies the expression 0.2<=(Lb / La)<=1.5 when the length per unit area of the grain boundaries of crystal grains the crystal orientation differences of which are 10 degrees or more is defined as La and the length per unit area of the grain boundaries of crystal grains the crystal orientation differences of which are less than 10 degrees is defined as Lb and further satisfies the requirements that the average value of D is 25 [mu]m or less and the area ratio of crystal grains satisfying the expression D<=30 [mu]m in the ferrite grains surrounded by the grain boundaries of crystal grains the crystal orientation differences of which are 10 degrees or more is 50% or more when the circle equivalent diameter of each of ferrite grains surrounded by the grain boundaries of crystal grains the crystal orientation differences of which are 10 degrees or more is defined as D; and has a tensile strength of 980 MPa or more.

The invention relates to a manufacture process of carbon steel and carbon steel hot rolling plate, in particular to a manufacture process of fine grain reinforcement carbon structural steel and hot rolling sheet plate of the steel. The invention mainly solves the technical problem that hot rolling plate of higher strength can not be produced on common completely continuous hot continuous rolling mill by use of common carbon structural steel at present. The fine grain reinforcement carbon structural steel adopts the following chemical composition (weight percent): 0.14 percent to 0.20 percent of C, 0.10 percent to 0.40 percent of Si, 0.65 percent to 0.90 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.015 percent of S and the rest, Fe. The manufacture process of the hot rolling sheet plate is as follows: a continuous casting slab which meets the requirements of compositions is heated to 1,210 DEG C to 1,250 DEG C; a rough rolling stage comprises five-pass tandem rolling and the end temperature of the rough rolling stage is between 1,050 DEG C and 1,060 DEG C; in addition, the thickness of an intermediate slab ranges from 35 mm to 45 mm. When rough rolling is finished, the intermediate slab is curled through a hot coil box and then is unfolded for finish rolling; a finish rolling stage comprises six-pass tandem rolling with the start rolling temperature ranging between 920 DEG C and 940 DEG C and the end temperature ranging between 820 DEG C and 860 DEG C; after finish rolling, the thickness of a steel plate is between 2 mm to 8 mm; in addition, a laminar flow cooling stage adopts forepart intensive cooling with the coiling temperature ranging from 520 DEG C to 620 DEG C.

Provided are a high-strength hot-dip galvanized steel sheet and a production method therefor, the hot-dip galvanized steel sheet maintaining a high yield ratio (YR) and a high bake hardening amount (BH amount) from the perspective of improving collision resistance performance, and having excellent material properties, in particular strength and internal uniformity of an elongated coil, at TS not less than 590 MPa. The hot-dip galvanized steel sheet has a structure that: contains, in mass%, 0.060%-0.13% C, 0.01%-0.7% Si, 1.0%-3.0% Mn, 0.005%-0.100% P, less than 0.010% S, 0.005%-0.100% sol. Al, less than 0.0100% N, 0.005%-0.10% Nb, and 0.03%-0.15% Ti; fulfills the relationship (Nb / 93+Ti* / 48) / (C / 12)>0.08 (Ti* = Ti-(48 / 14)N-(48 / 32)S); and includes ferrite having an average crystal particle diameter of less than 15 [mu]m and an area ratio of at least 80%, and martenite having an area ratio of 1%-15%.

Provided is a high-strength cold-rolled steel sheet having excellent elongation and stretch flangeability, and a high yield ratio, as well as a method for manufacturing same. A high-strength cold-rolled steel plate comprising 0.10-0.27% of C, 0.8-2.4% of Si, 2.3-3.5% of Mn, 0.08% or less of P, 0.005% or less of S, 0.01-0.08% of Al, and 0.010% or less of N (percentages given with respect to mass), the balance comprising Fe and inevitable impurities. The average ferrite crystal grain size is 5 [mu]m or less. Ferrite is present in a volumetric ratio of 3-20%, residual austenite is present in a volumetric ratio of 5-20%, and martensite is present in a volumetric ratio of 5-20%. Bainite and / or annealed martensite are included in the remainder. Said steel plate has a microstructure in which the total quantity of residual austenite, martensite, or a phase combined therefrom, in which the crystal grain size is 2 [mu]m or less, is 150 or more per 2000 [mu]m2 within a plate-thickness cross section parallel to the rolling direction of the steel plate.

A technology for producing nodular graphite cast iron QT800-6 features that it contains Ca (0.001-0.05 wt.%) and Ba (0.006-0.1) beside conventional components, and its heat treatment includes normalizing at 860+ / -40 deg.C for 1.5+ / -1.0 hr and tempering at 600+ / -50 deg.C for 2.0+ / -1.0 hr. Its casting features high tension strength, elongation, impact toughness and hardness, and low cost.

The invention provides a pipe corrosion-resistant multielement aluminium bronze alloy material and the ingredients are as follows: 4.0 to 10.0wt percent of Al, 1.0 to 4.5wt percent of Fe, 1.0 to 4.5wt percent of Mn, 0.8 to 4.0wt percent of Ni, 0.05 to 0.5wt percent of Cr and the balance of Cu and unavoidable impurities; in casting state, the tensile strength is more than 385MPa, the yield strength is more than 180MPa, the yield ratio is more than 0.48, and the specific elongation is more than 27 percent; in annealing state, the tensile strength is more than 525MPa, the yield strength is more than 285MPa, the yield ratio is more than 0.55, the specific elongation is more than 42 percent and the complete immersion uniform corrosion rate is 0.01 to 0.035mm / a; the copper alloy has excellent performance, is particularly suitable for the environment with high flow rate of seawater and is an ideal material for manufacturing sea water desalinating condenser equipment, shipping sea water condenser equipment and seashore power plant condensers.

Disclosed is a high yield ratio hot-dip galvanized steel sheet with excellent ductility and hole expansion properties and having a tensile strength: TS) of 590 MPa or greater; also disclosed is a manufacturing method thereof. The disclosed high yield ratio high-strength hot-dip galvanized steel sheet with excellent ductility and hole expansion properties contains, by mass%, C: between 0.04% and 0.13%, Si: between 0.9% and 2.3%, Mn: between 0.8% and 2.4%, P: less than 0.1%, S: .01% or less, Al: between 0.01% and 0.1%, N: 0.008% or less, with the remainder consisting of iron and inevitable impurities. The composition is 94% or more ferrite and 2% or less martensite by area ratio, the average grain size of the ferrite is 10[mu]m or less, the Vickers hardness of the ferrite is 140 or greater, the average grain size of the carbides present on the ferrite grain boundaries is 0.5[mu]m or less, and the aspect ratio of the carbides present on the ferrite grain boundaries is 2.0 or less.

This heat-treated steel sheet member has a chemical composition which includes, expressed in mass%, 0.05-0.50% of C, 0.50-5.0% of Si, 1.5-4.0% of Mn, not more than 0.05% of P, not more than 0.05% of S, not more than 0.01% of N, 0.01-0.10% of Ti, 0.0005-0.010% of B, 0-1.0% of Cr, 0-2.0% of Ni, 0-1.0% of Cu, 0-1.0% of Mo, 0-1.0% of V, 0-0.01% of Ca, 0-1.0% of Al, 0-1.0% of Nb, and 0-0.1% of REM, theremainder being Fe and impurities. The heat-treated steel sheet member has a metallographic structure which mainly consists of martensite, and which has a retained austenite volume fraction of 0.2-1.0%. The number density of carbides present in the steel sheet member which have a circle equivalent diameter of at least 0.1 Mum is not more than 4.0*103 per mm2. The heat-treated steel sheet member has a tensile strength of at least 1.4 GPa, and a yield ratio of at least 0.65.