Low-yield-strength fire-resistant anti-seismic building steel and production method thereof

The invention discloses low-yield-strength fire-resistant anti-seismic building steel and a production method thereof, and belongs to the technical field of metallurgy. The building steel comprises the following chemical components in percentage by mass: 0.005-0.015% of C, less than or equal to 0.05% of Si, less than or equal to 0.20% of Mn, less than or equal to 0.015% of P, less than or equal to 0.003% of S, 0.015-0.025% of Als, 0.008-0.015% of Nb, 0.010-0.025% of Ti, 0.015-0.025% of Mo, less than or equal to 0.0030% of N and the balance iron and inevitable impurities. The production method comprises the working procedures of smelting, continuous casting, casting blank heating, rolling and self-tempering. According to the building steel and the production method thereof, the internal stress of the steel plate is eliminated by adopting a self-tempering mode after rolling, the steel plate has low yield strength and excellent toughness, and the yield strength attenuation under the high-temperature condition is