Age hardening non-heat treated bainitic steel

• Main Authors: Haritani, Makoto, Tanimura, Yoshihiro, Nishiwaki, Tadashi, Fukuoka, Tomomitsu, Miyazaki, Takahiro, Morita, Kouji, Tanaka, Yuuki, Ito, Toshimasa
• Format: Patent
• Language: English
• Published: 18.08.2020
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

The present invention provides an age hardening type bainitic microalloyed steel having a composition which includes, in terms of mass%: 0.06-0.35% of C; 0.01-2.00% of Si; 0.10-3.00% of Mn; 0.001-0.200% of S; 0.001-2.00% of Cu; 0.40-3.00% of Ni; 0.10-3.00% of Cr; 0.10-1.00% of Mo; 0.10-1.00% of V; and 0.001-0.100% of s-Al, with the remainder being Fe and unavoidable impurities, and which satisfies a value of the following expression (1) to be 20 or larger and a value of the following expression (2) to be 0.82 or larger: 3 × C + 10 × Mn + 2 × Cu + 2 × Ni + 12 × Cr + 9 × Mo + 2 × V 1.66 × C + 0.18 × Si × 0.27 × Mn + 0.09 × Ni + 0.32 × Cr + 0.34 × Mo + 0.44 × V in which each [ ] in the expression (1) and the expression (2) indicates a content of the element shown therein in terms of mass%.