A method for manufacturing a steel plate with uniform longitudinal properties obtained by normalizing rolling

Abstract

The invention discloses a steel plate obtained by normalizing rolling to obtain uniform longitudinal performance and a manufacturing method thereof, wherein the components of the steel plate include C, Mn, Ti, Si, N, Als, P, S, and the balance of Fe and impurities, and the content of the above-mentioned component elements must be limited at the same time: 83%Si+354%N>23. The addition ratio of Si and N, supplemented by an appropriate amount of Mn, strictly controls the content of harmful elements P and S; the yield strength of the steel plate provided by the invention is 370~432MPa at room temperature, the tensile strength is 533~566MPa, and the elongation is 25 ~30.5%, ‑20°C impact energy is 185~231J, and the longitudinal strength difference of the same plate is 5~24MPa, and the tensile strength difference of the same plate is 2~17MPa. Equivalent mechanical properties, and uniform longitudinal properties, greatly reduce production costs, reduce technological processes, improve production efficiency and economic benefits, and have great promotional significance.

Description

Technical field[0001]The invention relates to the technical field of steel manufacturing, in particular to a method for normalizing rolling to obtain steel plates with uniform longitudinal properties.Background technique[0002]In recent years, the use of low-alloy steel plates in the market has become more and more extensive, and the quality requirements of low-alloy steel plates have become higher and higher, especially in some special geographic environments such as high-cold areas or key pressure-bearing structural parts. Low-alloy steel plates should have a more uniform structure, stable physical and chemical properties, and good fatigue resistance. In this regard, ordinary low-alloy steel sheets no longer meet the quality demands of customers. The normalizing process, as a heat treatment process that can refine austenite grains and improve the mechanical properties of steel plates, is widely used in structural steels. It can reduce the difference in longitudinal strength of the ...

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Problems solved by technology

[0005] The purpose of the present invention is to address the deficiencies in the prior art, to propose a method for manufacturing a steel plate with uniform longitudinal properties by normalizing rolling, and to solve the problem of poor uniformity in the longitudinal properties of the existing steel plates, or the cumbersome heat treatment process for obtaining steel plates with uniform longitudinal properties , long cycle, high cost and other issues, the thickness of the steel plate is 50-100mm, the process adopts normalizing rolling, the yield strength at room temperature is 370-432MPa, the tensile strength is 533-566MPa, and the elongation is 25-30.5%. The impact energy at -20°C is 185~231J, and the longitudinal strength difference of the same board is 5~24MPa, the tensile strength difference of the same board is 2~17MPa, and the longitudinal performance is uniform

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