Causes analysis and improving measures of sliver defect in 304 stainless stee

304 stainless steel is a nickel-containing austenitic stainless steel, which belongs to the Fe-Cr-Ni series alloy, and is the main representative brand of austenitic stainless steel. Due to insufficient cost advantages of 304 stainless steel and weak market profitability, in order to reduce costs and improve profitability, the company currently uses high-sulfur phosphorus pig iron as the raw material for smelting 304 stainless steel. Due to its relatively low cost, it is called "low-price nickel resources" ". With the large-scale use of low-priced nickel resources, under the existing raw material conditions, the original process technology can no longer meet the user's requirements for product quality. Therefore, it is necessary to study the process technology under the existing raw material conditions to meet low cost And high quality dual requirements.

In the production of 304 cold-rolled stainless steel plates, line-shaped defects often appear on the surface of the strip, which are called linear scales, or "line scales" for short. Line scale defects are mainly distributed in the range of unequal width from the two sides, and can only be observed after the cold-rolled sheet is pickled.

With reference to relevant effective measures taken in the practice of domestic stainless steel production, combined with the company's research results, a comprehensive analysis of the causes of line scale defects, and corresponding control measures, have certain reference significance for reducing stainless steel surface quality defects.

304 stainless steel wire scale defect introduction Baosteel Stainless Steel Company's steelmaking plant uses two-step smelting 304 stainless steel production process: electric furnace → AOD → IF → continuous casting →

The board is broken and repaired. The main processes that produce line scale defects are AOD, IF and continuous casting.

The 304 stainless steel wire scale defect is detected in the cold rolling APC unit. The shape is small and difficult to observe with the naked eye. The length is about 20-80mm and the width is 0.5 to 1.0mm. Such defects can be found on the upper and lower surfaces of the steel coil, showing intermittent and irregular distribution characteristics.

Its morphological characteristics are shown in Figure 1.