Pickling cold-formed steel and manufacturing method thereof

Abstract

The invention discloses pickling cold-formed steel and a manufacturing method thereof, and belongs to the technical field of steelmaking. The pickling cold-formed steel comprises the following chemical components in percentage by weight: less than or equal to 0.07% of C, less than or equal to 0.05% of Si, less than or equal to 0.45% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, less than or equal to 0.060% of Als, less than or equal to 0.0100% of N, and the balance of Fe and inevitable impurities. The manufacturing method comprises the following specific processing steps of: step 1, converter smelting; step 2, RH furnace refining; step 3, continuous casting; step 4, heating; step 5, rolling; step 6, cooling; step 7, coiling; step 8, pickling; and step 9, wetleveling. The microstructure of a hot-rolled steel plate manufactured by the manufacturing method is ferrite and pearlite, the yield strength of the product is 230-300 MPa, the tensile strength is 300-420 MPa, the elongation A50 is 38-45%, the 180-degree longitudinal bending test D =0a is qualified, the surface roughness of strip steel is 0.6-1.5, the surface whiteness of the strip steel is 55-65,the yellowness is 0.5-3.0, and the product has good yield ratio, elongation performance and cold bending performance, and has high-level roughness and surface gloss.

Description

technical field [0001] The invention relates to the technical field of steelmaking, more specifically, to a pickling cold-formed steel and a manufacturing method thereof. Background technique [0002] At present, hot-rolled pickling products are widely used in household appliances, automobiles, and pipe-making industries. The development of pickling cold-formed steel has become an inevitable trend. Cold-formed steel can not only bring huge economic benefits, but also expand hot-rolled pickling products. The scope of application is of great significance to promote the "hot-hot cooling" of pickling household appliances and steel sheets for automobiles. There are few patents declared for "hot instead of cold" pickling cold-formed steel and its manufacturing method. Example: Patent Title - Thin Gauge Hot Rolled Pickled Steel with Good Formability and Process for its Production. The production steps are molten iron desulfurization, converter smelting and alloying treatment, cont...

AI Technical Summary

Problems solved by technology

The product adopts the continuous casting and rolling process, which cannot clean and repair the milled surface and corner of the billet, which affects the surface quality of the strip steel. The Si content control range in the composition design is 0.10-0.30%, and the research shows that the Si content is ≥0.15%. When the strip steel surface is prone to red rust, there is a Si-enriched layer between the red rust and the strip steel matrix, which greatly increases the difficulty of removing the high-temperature oxide scale, which is unfavorable to the surface quality of the finished pickling coil.

In addition, the production of the product has undergone the smoothing and finishing processes separately, and there is a phenomenon of overlapping functions, which greatly increases the production cost of the product

At present, there is still no patent related to the production of pickled cold-formed steel with good surface quality and good formability through reasonable chemical composition design, rolling process and pickling process optimization without significantly increasing production costs

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