Smelting and rolling production method of 700 MPa-grade pearlite ferrite ultrahigh-strength construction steel bar

Abstract

The invention discloses a smelting and rolling production method of a 700 MPa-grade pearlite ferrite ultrahigh-strength building steel bar. The low-cost smelting and rolling production method of the 700 MPa-grade pearlite ferrite ultrahigh-strength building steel bar is proposed on the basis of an HRB600 high-strength steel bar, and the appearance of the building steel bar is still the same as that in the GB1499.2 national standard. The whole section of the building steel bar structure prepared through the method is a pearlite and ferritic structure, no tempered martensite structure exists on the edge of a base circle, the building steel bar structure is suitable for building steel bars with the diameter phi ranging from 8 mm to 40 mm, and after rolling, the yield strength is larger than or equal to 700 MPa, the tensile strength is larger than or equal to 820 MPa, A is larger than or equal to 12%, and Agt is larger than or equal to 7%.

Description

technical field [0001] The invention relates to the technical field of smelting, in particular to a smelting and rolling production method of 700MPa pearlitic ferrite ultra-high-strength building steel bars. Background technique [0002] With the rapid development of my country's urbanization and the continuous increase of construction scale, the construction industry, as a pillar industry, supports my country's economic development, affects and drives the prosperity and development of social economy. Steel bars with a yield strength of 400MPa and above are called high-strength steel bars. The yield strength levels in the existing domestic construction steel bar standards mainly include 400MPa, 500MPa, and 600MPa. The microstructure is required to be pearlite + ferrite. At present, most of the building steel bars with a yield strength exceeding 600MPa are bainite in the market, and it is difficult to control the rolling production and external dimensions, and the product tou...

AI Technical Summary

Problems solved by technology

Steel bars with a yield strength of 400MPa and above are called high-strength steel bars. The yield strength levels in the existing domestic construction steel bar standards mainly include 400MPa, 500MPa, and 600MPa. The microstructure is required to be pearlite + ferrite. At present, most of the building steel bars with a yield strength exceeding 600MPa in the market are bainite, and it is difficult to control the rolling production and external dimensions, and the product toughness is poor.

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