Rolled steel and rolled steel inclusion control method

Abstract

The invention relates to a rolled steel and rolled steel inclusion control method. The rolled steel is produced by the following control method of (1), converter smelting; (2), RH furnace refining; (3), LF furnace refining; and (4) continuous casting protection casting; in the LF furnace refining stage in the step (3), soft blowing and calcium treatment are carried out, the primary soft blowing is carried out for 3-5 min, the flow is 200-800 NL / min, the calcium treatment wire feeding amount is 160-220 m / furnace, it is ensured that the Ca content of out-of-station is 20-35 ppm or Ca / Als is larger than or equal to 0.08, the secondary soft blowing is carried out for 12-18 min after calcium treatment, the flow is 80-220 NL / min, aluminum, alloy and heating operations are forbidden in the soft blowing and calcium treatment process, and molten steel exposure is strictly forbidden in the soft blowing process. According to the control method, the quality of rolled steel products can be improved, the quality objection rate is reduced, and the purposes of reducing cost and improving efficiency are finally achieved.

Description

technical field [0001] The invention relates to the technical field of iron and steel, in particular to a method for controlling rolling steel and rolling steel inclusions. Background technique [0002] With the continuous development of the industry, the chrome-plated steel strip obtained by cold-rolling rolled steel to a thickness of 0.1 mm and performing chrome plating has been widely used in food packaging and optical cable industries. In the production of rolled steel, aluminum deoxidation is usually used for refining in steel mills, and Al is generated at the end of deoxidation. 2 o 3 and aluminate inclusions, in order to meet the high cleanliness requirements of ultra-thin chrome-plated optical cables, calcium treatment is required to remove Al 2 o 3 and aluminate inclusions; light calcium treatment, improper soft blowing treatment, easy to generate CaO·2Al 2 o 3 and CaO·6Al 2 o 3 , these calcium aluminates gather and grow inside the tundish or nozzle, are wash...

AI Technical Summary

Problems solved by technology

During the process of cold rolling to 0.1mm chrome plating by downstream customers, large inclusions (inclusions with a size > 50 μm) will be exposed intensively, which will further cause holes in the finished product or breakage during the drawing process, affecting the normal use of customers and the yield of finished products Low

[0003] In order to control the surface quality and inclusions of the slab, some steel mills use the surface polishing technology to remove the surface defects and inclusions of the slab. The polishing depth is about 10-20mm, and the production efficiency and yield are low.