Moldings as well as methods for their preparation, such as fasteners or pivot class of screws and bolts, etc. and excellent excellent steel and strength in cold heading of a high strength

摘要

PROBLEM TO BE SOLVED: To provide steel which causes neither recess crack nor defects similar to it even if formed into a formed article without heat treatment and has a high level of strength even if refining treatment is omitted.;SOLUTION: The steel with high strength and excellent cold headability has a chemical composition containing 0.45 mass% C and a structure having ferritic structure as a primary phase and has mechanical properties of ≥65% reduction of area and ≥600 MPa tensile strength. Further, the steel is free of quenching or quench-and-temper treatment. By using this steel, the formed articles, such as fastening parts and shafts, are obtained.;COPYRIGHT: (C)2005,JPO&NCIPI