Low carbon 420 MPa grade composite fortified ultr-fine crystal grain band steel

Abstract

A 420 MPa-class low-carbon band steel with superfine crystal grains contains C (0.10-0.14 wt.%), Si (0.18-0.40), Mn (0.85-1.10), P (0-0.01), S (0-0.01) and Fe (rest), and is prepared through smelting, conticasting, heating, rolling twice, cooling and winding. Its advantages are multi-phase structure including ferrite, bainite and pearlite, high yield strength (420-450 MPa), high tension strength (530-550 MPa) and low cost. It can replace high-strength low-alloy steel.

Description

Technical field [0001] The invention relates to a low-carbon high-strength steel, in particular to a low-carbon 420MPa grade composite strengthened ultra-fine-grain strip steel formed by controlled rolling and controlled cooling of low-carbon structural steel. Background technique [0002] At present, iron and steel materials are still the main body of structural materials. However, with the development of society and economy, the steel industry is under increasing pressure to save resources, save energy, and protect the environment. Therefore, it has become a hot spot in the field of iron and steel research to use special processing techniques for traditional iron and steel materials to greatly improve their performance, prolong their service life, and effectively improve resource utilization and recovery. [0003] In 1997 and 1998, Japan and South Korea successively launched a research program on structural materials for the 21st century. The goal is to double the practic...

AI Technical Summary

Problems solved by technology

Whether it is from the mechanical properties of the above steel or from the metallographic structure of the steel, it can be explained that the tensile strength of super-SS400 obtained in the experiment is still low, and the yield strength is relatively large, which makes the formability in the application poor; The gap in performance data is large, indicating that this technical scheme can improve the process conditions of the existing carbon-manganese steel with a yield strength of 200MPa to 400MPa structural steel, which still needs to be further studied and solved.

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