2 results about "Ferritic matrix" patented technology

This invention belongs to the field of metallurgical technology, and specifically relates to a high-surface-quality steel plate without transverse crease defects and its production method. The chemical composition, by weight percentage, is: C: 0.082%–0.104%, Si: 0.06%–0.10%, Mn: 0.32%–0.39%, P≤0.010%, S≤0.004%, O≤0.0015%, Alt: 0.025%–0.048%, N: 0.0012%–0.0025%, V: 0.014%–0.026%, B: 0.0006%–0.0016%, with the remainder being Fe and unavoidable impurities. By adding elements V and B, combined with hot rolling and leveling processes, the content of dissolved carbon and nitrogen atoms in the ferrite matrix is ​​reduced, allowing carbon and nitrogen atoms to exist in the form of precipitated phases. This reduces the formation of Cotillard atmospheres, lowers the stress difference between the upper and lower yield points, and results in stable coiling performance and excellent surface quality of the steel plate.

The application discloses a non-adjustable steel with excellent fatigue resistance for automobile crankshafts and a production method thereof. The non-adjustable steel has the following chemical components in percentage by weight: C: 0.30-0.50%, Si: 0.25-0.60%, Mn: 0.50-2.00%, Cr: 0.15-0.45%, Nb+V+Ti: 0.10-0.35%, Al: 0.05-0.15%, S: 0.035-0.075%, P: less than or equal to 0.015%, Mg+Te: 0.01-0.03%, and the balance of Fe and inevitable impurities. The production method comprises the following steps: heating a steel billet, rolling and forging. The steel provided by the application has the following advantages: the rod material has a uniform structure of ferrite matrix + lamellar pearlite + intracrystalline ferrite, has good comprehensive mechanical properties of tensile strength and elongation after fracture, and has excellent fatigue resistance.