Jfe Steel Corporation

Thyssenkrupp Steel Europe Ag

Fusae Shiimori

Takashi Kobayashi

Takeshi Yokota

Katsumi Kojima

Shinjiro Kaneko

Yoshiyasu Kawasaki

Nobusuke Kariya

Daisuke Otani

Yuji Tanaka

Yasunobu Nagataki

Kazuhiro Seto

Takaaki Tanaka

Yuki Toji

Hidekazu Minami

Hayato Saito

Thomas Heller

Brigitte Hammer

Richard Georg Thiessen

Frank Hisker

Almir Dzafic

Richard Thiessen

Takafumi Jingu

Daisuke Ootani

Provided is a steel sheet for cans with high strength and sufficiently high formability particularly as a material for a can body with a neck portion. The steel sheet for cans of the present disclosure has a chemical composition containing, in mass %, C: 0.010% to 0.130%, Si: 0.04% or less, Mn: 0.10% to 1.00%, P: 0.007% to 0.100%, S: 0.0005% to 0.0090%, Al: 0.001% to 0.100%, N: 0.0050% or less, Ti: 0.0050% to 0.1000%, B: 0.0005% to less than 0.0020%, and Cr: 0.08% or less, where 0.005≤(Ti*/48)/(C/12)≤0.700 is satisfied; and a microstructure with a proportion of non-recrystallized ferrite of 3% or less, wherein an upper yield stress is 550 MPa to 620 MPa.

Steel sheet for cans and method of producing same

Provided is a steel sheet for cans. A steel sheet for cans comprises: a chemical composition containing, in mass %, C: 0.010% or more and 0.130% or less, Si: 0.04% or less, Mn: 0.10% or more and 1.00% or less, P: 0.007% or more and 0.100% or less, S: 0.0005% or more and 0.0090% or less, Al: 0.001% or more and 0.100% or less, N: 0.0050% or less, Ti: 0.0050% or more and 0.1000% or less, and Cr: 0.08% or less, and satisfying a relationship 0.005≤(Ti*/48)/(C/12)≤0.700 where Ti*=Ti−1.5S, with a balance consisting of Fe and inevitable impurities; a microstructure in which a proportion of cementite in ferrite grains is 10% or less; and an upper yield strength of 550 MPa or more.

Provided is a high-strength steel sheet having excellent ductility, bendability, and TS of 500 MPa or more, in particular, a high-strength thin steel sheet for cans having a sheet thickness of 0.1 to 0.8 mm, the steel sheet having a chemical composition containing C: 0.03-0.15%, Si: 0.01-0.05%, Mn: more than 0.6% and 1.5% or less, P: 0.025% or less, S: 0.02% or less, Al: 0.01-0.10%, N: 0.0005-0.0100%, Ti: 0.005-0.020%, B: 0.0005-0.0100%, and Nb: 0.0050-0.0200% with the balance being Fe and inevitable impurities, in which the steel sheet has a metallic structure containing, in area ratio, 85% or more of ferrite and 1-10% of martensite, the martensite has a grain size of 5 μm or less, and a ratio of martensite having a grain size of 2 μm or less is 80% or more.

High-strength steel sheet and method for producing same

There is provided a high-strength steel sheet and a method for producing the same. The high-strength steel sheet has a specified chemical composition and a steel microstructure including, by area fraction, 75.0% or more tempered martensite, 1.0% or more and 20.0% or less fresh martensite, and 5.0% or more and 20.0% or less retained austenite. A hardness ratio of the fresh martensite to the tempered martensite is 1.5 or more and 3.0 or less, the ratio of the maximum KAM value in the tempered martensite in the vicinity of the heterophase interface between the tempered martensite and the fresh martensite to the average KAM value in the tempered martensite is 1.5 or more and 30.0 or less, and the average of ratios of grain sizes of prior austenite grains in the rolling direction to those in the thickness direction is 2.0 or less.

High-strength steel sheet and method for producing the same

A high-strength steel sheet exhibiting excellent ductility and stretch-flangeability, and a method for manufacturing such a high-strength steel sheet. The high-strength steel sheet has a chemical composition including specific proportions of components in which C/Mn is 0.08 to 0.20, the balance being iron and inevitable impurities, and includes microstructures including, in terms of area fraction relative to all the microstructures, 40% to 70% total of ferrite and bainitic ferrite, 5% to 35% martensite and 5% to 30% retained austenite. The proportion of martensite (including retained austenite) adjacent to bainitic ferrite is not less than 60% of all martensite (including retained austenite). The proportion of 4.0 GPa and smaller differences in microhardness measured at 0.5 &#x3bc;m intervals is not less than 70%. The proportion of microstructures with 8.0 GPa or smaller microhardness is not less than 85% of all the microstructures.

High-strength steel sheet and method for manufacturing the same

A method for producing a cold-rolled steel strip with a yield ratio Re/Rm of at least 0.7, the cold-rolled steel product including iron, unavoidable impurities and (in wt. %) C: 0.05-0.20%, Si: 0.25-1.00%, Mn: 1.0-3.0%, Al: 0.02-1.5%, Cr: 0.1-1.5%, N: &#x3c;0.02%, P: &#x3c;0.03%, S: &#x3c;0.05% and optionally one or more of Ti, Mo, Nb, V, and B, Ti: up to 0.15%, Mo: &#x3c;2%, Nb: &#x3c;0.1%, V: &#x3c;0.12%, and B: 0.0005-0.003%. The cold-rolled flat steel product undergoes heat treatment for 4.5-24 hours at a temperature of 150-400&#xb0; C. Also, a cold rolled flat steel product discussed above having a structure including at least two phases, selected from (in vol. %) at least 10% tempered martensite, &#x3c;10% bainite, &#x3c;10% residual austenite and remainder ferrite, a yield ratio of at least 0.7, a tensile strength of &#x2265;750 MPa and a hole expansion of at least 18%.

Method for producing a cold-rolled flat steel product with high yield strength and flat cold-rolled steel product

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Tokyo, Japan

Fusae Shiimori