High-strength and high-toughness hot-rolled magnet yoke steel with yield strength greater than or equal to 650 MPa and production method

Abstract

A high-strength and high-toughness hot-rolled magnet yoke steel with yield strength greater than or equal to 650 MPa comprises the following components in percentage by weight: 0.01-0.03% of C, less than or equal to 0.15% of Si, 1.45-1.75% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, 0.04-0.08% of Ti, 0.01-0.02% of Nb, 0.02-0.10% of Als, and less than or equal to 0.010% of N. The production method comprises the following production steps: pouring after molten iron desulphurization, converter combined blowing and vacuum treatment; heating slabs; roughly rolling; precisely rolling; carrying out laminar cooling; and coiling. The yield strength of the magnet yoke steel is greater than or equal to 650 MPa, the tensile strength is greater than or equal to 750 MPa, the elongation is greater than or equal to 13%, the impact energy KV2 is greater than or equal to 80 J at the temperature of minus 20 DEG C, the magnetic induction performance B50 is greater than or equal to 1.50 T, and requirements of high-strength and high-magnetic-induction-performance steels for high-unit-capacity ultra-large hydro-generator rotor magnet yokes can be met.

Description

technical field [0001] The invention relates to a hydraulic generator rotor yoke steel and a production method thereof, in particular to a high-strength and high-toughness hot-rolled yoke steel with yield strength ≥ 650 MPa and a production method thereof. Background technique [0002] With the implementation of the "Western Development" strategy and the "West-to-East Electricity Transmission" strategy determined by our country, and in accordance with the national guideline of "vigorously developing hydropower", a large number of large-scale hydropower projects will start construction in the next few decades. With the development of the hydropower industry, the performance requirements for the yoke steel plate used in the key part of the rotor yoke of the hydro-generator have also increased from simple high strength to high toughness, especially in severe cold regions. The service environment of steel is harsh, and once the material breaks during the operation of the rotor, ...

AI Technical Summary

Problems solved by technology

However, this level of toughness steel can no longer adapt to and meet the current generator requirements of large-scale hydropower projects, so it is urgent to research and develop high-strength and high-toughness yoke steel

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