High-strength and high-toughness hot rolled magnetic yoke steel with yield strength to be 550MPa grade and production method

Abstract

The invention discloses high-strength and high-toughness hot rolled magnetic yoke steel with the yield strength to be a 550MPa grade. The high-strength and high-toughness hot rolled magnetic yoke steel is prepared from the following components in percentage by weight: 0.01-0.03 percent of C, smaller than or equal to 0.15 percent of Si, 1.00-1.40 percent of Mn, smaller than or equal to 0.025 percent of P, smaller than or equal to 0.015 percent of S, 0.04-0.08 percent of Ti, 0.02-0.10 percent of Als and smaller than or equal to 0.010 percent of N. The high-strength and high-toughness hot rolled magnetic yoke steel is prepared through the following production steps: pouring after hot metal desulphurization, converter combined blowing and vacuum treatment; heating a slab; rough rolling; finish rolling; laminar cooling; and reeling. According to the high-strength and high-toughness hot rolled magnetic yoke steel disclosed by the invention, the yield strength is larger than or equal to 550MPa, the tensile strength is larger than or equal to 650MPa, the ductility A is larger than or equal to 15 percent, the impact energy KV2 at 20 DEG C below zero is larger than or equal to 100J, the magnetic induction performance B50 is larger than or equal to 1.50 T, and the demand of a large hydro-generator rotor magnetic yoke with high unit capacity for using the high-strength and high-toughness hot rolled magnetic yoke steel 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 a yield strength of 550 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 roto...

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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