Titanium microalloyed hot rolled strip and manufacturing method thereof

Abstract

The invention provides a titanium composite microalloyed hot rolled strip and a manufacturing method thereof. The hot rolled strip comprises the following components by weight percentage: 0<C<=0.005, 0<N<=0.004, 0<Si<=0.03, Mn 0.10-0.20, 0<P<=0.018, 0<S<=0.015, Al 0.02-0.06, 0<Ti<=0.070, 0<O<=0.002, 0<Cr<=0.05, 0<Ni<=0.07, 0<Cu<=0.07 and 0<Mo<=0.020. The manufacturing method comprises the steps of preparing continuous castings according to the constituent requirement and processing the continuous castings into the hot rolled strip. The continuous castings are heated to the temperature more than 1200 DEG C during hot rolling, the holding time is longer than 2.5h and weakly reducing atmospheres are adopted for heating; the finishing temperature of the hot rolled strip is 880-930 DEG C; after finish rolling, the hot rolled strip is quickly water-cooled to the temperature of 680-750 DEG C to be reeled up; the telescoping of the coil is controlled to be less than or equal to 50mm and then the coil is cooled to the room temperature in the air. The surface quality of the strip prepared by the invention is good.

Description

Technical field [0001] The invention relates to a titanium microalloyed hot-rolled steel strip and a manufacturing method thereof. Background technique [0002] The automobile industry has always been a pillar industry in the economies of developed countries and an important industry in some developing countries. Since 2001, with the rapid development of my country's automobile industry, the demand for automobile steel has increased substantially. At present, automobile steel is still dominated by steel plates, and the weight of steel plates for cars accounts for about 50% of the total weight of cars. [0003] With the continuous improvement of the requirements for the use of cars and the development of car manufacturing technology, from the aspect of stamping performance, the steel plates for cars have been represented by the first generation stamping steel represented by low-carbon rimmed steel, and low-carbon aluminum killed steel as the representative The second-generation st...

AI Technical Summary

Problems solved by technology

[0008] In order to achieve the above purpose, and solve the problem that the moderate scale defects or serious scale defects on the surface of the hot-rolled steel strip cannot be removed in the pickling before cold rolling, which limits the pickling rate and causes the degradation of cold-rolled finished products, and at the same time for To avoid the adverse effects of moderate mechanical indentation defects or severe mechanical indentation defects on the surface of hot-rolled steel strips on the surface quality, formability and yield of finished cold-rolled steel strips, the present invention mainly adopts the chemical composition and hot-rolling process system Reasonable matching, producing a high surface quality Nb, Ti composite microalloyed IF hot-rolled steel strip