C-Mn-Ti-Nb series hot-rolled high strength high magnetic induction performance steel and manufacturing method thereof

Abstract

The invention discloses a preparing method of C-Mn-Ti-Nb system hot-rolled high-intensity and high magnetic property steel in microalloy steel producing domain, which comprises the following steps: a, allocating mass percent of each element as 0.03%-0.15% C, Si<=0.15%, 1.00%-1.80% Mn, P<=0.025%, S<=0.015%, 0.08%-0.18% Ti, 0.02%-0.07% Nb, 0.02%-0.10% Al, N<=0.010% and Fe; desulfurizing with iron melt; b, composite-blowing converter top and bottom; c, blowing argon gas from rear; d, casting to bar plate; e, choosing hot-continuous rolling mill device; heating the bar plate from step d at 1230-1280 deg.c; roughing down with the ending temperature at >=1100 deg.c; planishing with the ending temperature at 850-930 deg.c; cooling with lamellar flow; winding with the temperature at 550-620 deg.c; getting the product.

Description

technical field [0001] The invention relates to the field of microalloyed steel manufacturing, in particular to a steel with high strength (ReL≥700MPa) and high magnetic induction performance required by the rotor yoke of a large hydroelectric generator and a manufacturing method thereof. Background technique [0002] With the increasingly prominent contradiction between power supply and demand, clean, pollution-free and renewable hydropower has become an important measure to solve energy problems in our country. With the deepening of my country's western development, a large number of large-scale and giant hydropower projects of the Three Gorges level will start construction in the next few decades. These large-scale and giant hydropower projects all require large-scale hydropower generation with a single-unit capacity of 700,000 to 800,000 kilowatts. The unit, which puts forward the requirements of high strength and high magnetic induction performance for the steel used in ...

AI Technical Summary

Problems solved by technology

Before the application of the present invention, the Chinese invention patent No. 98800888.2 recorded a "method for producing grain-preferentially oriented electrical steel sheets with high magnetic induction based on the low-temperature slab heating method". The production line is long, annealing from hot-rolled steel plate to cold-rolled steel plate, and finally decarburization treatment is required, the production cycle is long, energy consumption is large, and the steel plate contains a relatively high content of silicon (Si) or a certain amount of copper (Cu) , nickel (Ni), chromium (Cr), boron (B), the cost of the alloy is relatively high, and the variety involved in the invention does not have high tensile strength

The Chinese invention patent with the application number 200480002119.7 introduces a "ultra-high-strength hot-rolled steel and a method for producing strips". In the process, it is necessary to control the rolling temperature below 950°C, then cool to 400°C or lower, maintain a cooling rate of more than 50°C / S between 800°C and 700°C, and finally cool at 250°C or more Coiling at low temperature, which requires extremely high capacity of rolling mill and coiling equipment, and will cause great damage to equipment, and has no operability. At the same time, the variety involved in this patent does not have high magnetic induction performance