A control method for steel defects in cold-rolled titanium-containing ultra-low carbon steel

Abstract

A method for controlling defects of titanium-containing ultra-low carbon steel cold-rolled steel, the composition weight percentage of the titanium-containing ultra-low carbon steel is: C≤0.005%, Si≤0.05%, Mn 0.05-0.3%, Al 0.05-0.1 %, Ti 0.008‑0.05%, P≤0.05%, S≤0.02%, N≤0.003%, T.O 0.0010‑40%, remaining Fe and unavoidable impurities, Al content ≥ Ti content; after RH vacuum decarburization, first Adding Ti, the amount of Ti added is controlled at the lower limit of the finished product value; adding Al, the added amount is controlled at the middle value of the finished product, and the circulation time of molten steel is ≥ 3min; adding other alloying elements and / or adjusting the composition of molten steel according to the specifications of the finished product, steel Liquid circulation time ≥ 2min; add rare earth metals Ce and La, the addition amount is according to the mass ratio REM / T.O=0.6-3.0, rare earth REM mass unit kg, total oxygen T.O in steel, unit ppm; molten steel circulation time ≥ 2min, molten steel Oxide Ce 2 o 3 ·Al 2 o 3 or La 2 o 3 ·Al 2 o 3 .

Description

technical field [0001] The invention relates to a steel-making process technology, in particular to a method for controlling cold-rolled steel defects of titanium-containing ultra-low carbon steel. Background technique [0002] With the advancement of technology, users have higher and higher requirements for steel quality. For ultra-low carbon steel, there is already a demand for cold-rolled finished sheets as thin as 0.05mm thick. The thinner the thickness of the cold-rolled product, the more likely deoxidized inclusions (Al 2 O 3 ) caused by steel defects, and cracking problems caused by deoxidized inclusions are also prone to occur during the user's stamping process. [0003] In the smelting of ultra-low carbon steel, oxygen (free oxygen and combined oxygen) added in converter smelting is the most important source of oxygen in the whole smelting process. During the subsequent tapping process, molten steel and steel slag containing a large amount of oxygen enter the lad...

AI Technical Summary

Problems solved by technology

But the inventor finds, both are in liquid state in molten steel, cause Al in steel 2 o 3 The inclusions are agglomerated into large-sized particles, and these large-sized inclusion particles are an important reason for the deterioration of the quality of subsequent finished products

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