5results about How to "High yield ratio" patented technology

This invention discloses a heat treatment method for improving the yield strength ratio of steel used in continuous extrusion dies. Specifically, the steel is subjected to the following sequential heat treatments: high-temperature normalizing, low-temperature normalizing, spheroidizing annealing, high-temperature quenching, high-temperature tempering, and low-temperature tempering. The high-temperature normalizing temperature is 1070℃~1100℃; the low-temperature normalizing temperature is 710℃~730℃; the spheroidizing annealing temperature is 840℃~870℃; the high-temperature quenching temperature is 1070℃~1100℃; the high-temperature tempering temperature is 620℃~640℃; and the low-temperature tempering temperature is 530℃~550℃. The yield strength ratio of the die steel after heat treatment using this method is ≥0.91, and the hardness is 48~52 HRC.

The present application discloses a high magnetic induction non-oriented electrical steel sheet, which contains Fe and inevitable impurities, and further contains chemical elements with mass percentage as follows: C≤0.003%, Si: 1.2-3.0%, Mn: 0.1-0.6%, P: 0.01-0.15%, Al: 0.1-0.4%, Ni: 0.05-1.0%; and satisfies Si+Al: 1.3-3.2%; and does not contain Sn and Sb. In addition, the present application further discloses a manufacturing method of the above high magnetic induction non-oriented electrical steel sheet, which comprises the following steps: (1) smelting and casting; (2) heating, rough rolling, finish rolling and coiling: wherein the thickness of the intermediate blank after rough rolling is controlled to be 20-45 mm, and the thickness of the sheet after finish rolling is 1.2-2.0 mm; and after coiling, aging treatment is carried out in the range of 550-650 ℃ during temperature drop for 1-4 h, so that the proportion of equiaxed crystal with the ratio between long and short axes between 1.0-4.0 in the microstructure of the sheet is ≥75%; (3) pickling; (4) primary cold rolling; (5) continuous annealing; (6) insulation coating.

This invention discloses a method for preparing medium-strength rails with a high yield strength ratio, comprising the following steps: subjecting the slab obtained from continuous casting to segmented step heating, wherein the heating temperature of each segment gradually increases and the heating time of each segment is ≥30 minutes; rolling the slab heated by segmented step heating using a rolling mill to produce a rail with residual heat, wherein the final rolling temperature of the rail head and rail base is controlled at 900–950°C; spraying a cooling medium on the final rolled rail head to accelerate the cooling rate and cooling it to 500–550°C; reheating the final rolled rail base to reduce the cooling rate and cooling it to 650–700°C; subsequently, allowing the rail to cool naturally in air to room temperature; and straightening the rail cooled to room temperature. Using this method, the yield strength ratio and tensile strength of the rail can be effectively improved, significantly enhancing the rail's plastic stability limit.

The present invention provides a cold rolled steel material including, by weight, 0.04% to 0.07% of carbon (C), 0.1% to 0.3% of silicon (Si), 1.1% to 1.5% of manganese (Mn), 0.015% to 0.06% of aluminum (Al), more than 0% to 0.02% of phosphorus (P), more than 0% to 0.005% of sulfur (S), 0.02% to 0.04% of niobium (Nb), 0.17% to 0.23% of titanium (Ti), more than 0% to 0.1% of chromium (Cr), more than 0% to 0.005% of nitrogen (N), and a balance of iron (Fe) and other inevitable impurities, and having a yield strength (YS) of 600 MPa to 900 MPa, an elongation (EL) of 8% or more, and a yield ratio (YR) of 95% or more.

This invention discloses a cold-rolled hot-dip aluminized zinc-coated steel sheet with a yield strength of 350 MPa, mainly addressing the technical problems of large hole diameter variation rate, unstable yield strength, and low work hardening index in existing cold-rolled hot-dip aluminized zinc-coated steel sheets after processing. The technical solution is a cold-rolled hot-dip aluminized zinc-coated steel sheet with a yield strength of 350 MPa, the chemical composition of its substrate by weight percentage is: C: 0.15%–0.19%, Si: 0.05%–0.10%, Mn: 0.40%–0.60%, P≤0.015%, S≤0.015%, Nb: 0.025%–0.035%, Cr: 0.05%–0.15%, Al: 0.010%–0.030%, with the remainder being Fe and unavoidable inclusions. The yield strength ratio of the cold-rolled hot-dip aluminized zinc-coated steel sheet is 0.85–0.93, and the n value is 1.5–1.7; it is used for structural components in the home appliance and electrical cabinet industries.