A low-cost cold-rolled magnetic pole steel with a yield strength of 450mpa and high magnetic induction and its manufacturing method

Abstract

The invention discloses high-magnetic-strength low-cost cold-rolled magnetic pole steel with the yield strength being 450 MPa and a manufacturing method thereof. The steel comprises, by mass, 0.05%-0.09% of C, 0.75%-1.15% of Mn, no more than 0.025% of P, no more than 0.01% of S, 0.015%-0.05% of Al, no more than 0.01% of N, 0.005%-0.02% of Nb, 0.05%-0.09% of Ti, and the balance Fe and inevitable impurities; and the content of Ti is larger than or equal to 0.03%+3.43*N. The high-magnetic-strength low-cost cold-rolled magnetic pole steel is simple in chemical component, and the cost is greatly lowered due to adding of the cheap Ti; the continuous annealing mode is adopted, the product performance uniformity is obviously improved, the lower yield strength ReL of the manufactured magnetic pole steel is higher than or equal to 450 MPa, and the magnetic induction intensity B50 of the manufactured magnetic pole steel is higher than or equal to 1.6 T; the steel plate strength and the magnetic induction strength are well matched, and the product has more excellent comprehensive performance.

Description

technical field [0001] The invention relates to a cold-rolled magnetic pole steel, in particular to a low-cost cold-rolled magnetic pole steel with a yield strength of 450 MPa and high magnetic induction and a manufacturing method thereof. Background technique [0002] The magnetic pole is the key component of the rotor of the hydro-generator. In order to ensure the balance and stability of the high-speed operation of the unit, the magnetic pole has high dimensional accuracy and sufficient strength. In order to reduce the eddy current loss of the unit, the magnetic pole steel plate must have excellent magnetic induction. With the development of hydropower units, more stringent technical requirements are put forward for the strength, plasticity, precision, wear resistance and process performance of magnetic pole materials. At present, only a few developed countries in the world, such as Japan, Germany, and the United States, can produce high-quality magnetic pole plates. Befo...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent CN200610019773.X discloses a production method of 450MPa grade cold-rolled magnetic pole steel. This method adopts bell furnace annealing, and the production time is long and the cost is high; more expensive Nb alloy elements are added; the magnetic properties of the material need to be further improved

Chinese patent CN200910049782.7 discloses a continuous annealing method for cold-rolled magnetic pole steel with a yield strength of 500 MPa. In order to meet the requirements of high yield strength, it adopts high C, Mn, Nb, Ti and V alloys, and the manufacturing cost is high, and Si Addition is not conducive to the surface quality control of hot-rolled strip steel, and it is easy to produce "red iron sheet" defects. At the same time, the magnetic properties of cold-rolled magnetic pole steel with yield strength of 500MPa are much lower than those of 450MPa-level magnetic pole steel.

Images