Patent classifications
C21D8/0268
FERRITIC STAINLESS STEEL HAVING IMPROVED CORROSION RESISTANCE, AND METHOD FOR MANUFACTURING SAME
Disclosed are a ferritic stainless steel having improved corrosion resistance and a method for manufacturing same. The ferritic stainless steel according to an embodiment of the present disclosure includes, in percent by weight (wt%), 0.001 to 0.05% of C, 0.001 to 0.05% of N, 0.1 to 1.0% of Si, 0.1 to 1.0% of Mn, 12.0 to 22.0% of Cr, 0.01 to 1.0% of Ti, and 0.01 to 1.0% of Nb, with the balance being Fe and inevitable impurities, wherein an area ratio of microdefects is 2% or less, and a sulfur (S) content in a surface film within 5 mm from the surface is 10% or less.
High-strength steel sheet and production method thereof
A high-strength steel includes a steel structure with: in area fraction, 60.0% to less than 90.0% of ferrite, 0% to less than 5.0% of unrecrystallized ferrite, 2.0% to 25.0% of martensite, 0% to 5.0% of carbide, and 0% to 3.0% of bainite; in volume fraction, more than 7.0% of retained austenite; in a cross-sectional view of 100 μm×100 μm, a value obtained by dividing number of retained austenite that are not adjacent to retained austenite whose crystal orientations are different by a total number of retained austenite being less than 0.80, an average crystal grain size of the ferrite being 6.0 μm or less, an average crystal grain size of the retained austenite being 3.0 μm or less, and a value obtained by dividing, by mass %, an average content of Mn in the retained austenite by an average content of Mn in steel being 1.50 or more.
Method for producing a flat steel product made of a manganese-containing steel, and such a flat steel product
The invention relates to a method for producing a flat steel product made of a medium manganese steel having a TRIP/TWIP effect. The aim of the invention is to achieve an improvement in the yield strength when a sufficient residual deformability of the produced flat steel product is obtained. This aim is achieved by the following steps: cold rolling a hot or cold strip, annealing the cold-rolled hot or cold strip at 500 to 840° C. for 1 minute to 24 hours, temper rolling or finishing the annealed hot or cold strip to form a flat steel product having a degree of deformability between 0.3% and 60%. The invention further relates to a flat steel product produced according to said method and to a use thereof.
AUSTENITIC STAINLESS STEEL AND METHOD OF MANUFACTURING THE SAME
A high-strength austenitic stainless steel, which has good hydrogen embrittlement resistance and hydrogen fatigue resistance, has a chemical composition including, in mass %, C: up to 0.10%; Si: up to 1.0%; Mn: not less than 3.0% and less than 7.0 %; Cr: 15 to 30%; Ni: not less than 12.0% and less than 17.0%; Al: up to 0.10%; N: 0.10 to 0.50%; P: up to 0.050%; S: up to 0.050%; at least one of V: 0.01 to 1.0% and Nb: 0.01 to 0.50%; and other elements, the balance being Fe and impurities, wherein the ratio of the minor axis to the major axis of the austenite crystal grains is greater than 0.1, the crystal grain size number of austenite crystal grains is not lower than 8.0, and the tensile strength is not less than 1000 MPa.
FERRITE-BASED STAINLESS STEEL PLATE, STEEL PIPE, AND PRODUCTION METHOD THEREFOR
A ferritic stainless steel sheet and a steel pipe as a material suitable for a heat-resistant component that is required to have especially excellent formability are provided. The ferritic stainless steel sheet contains 10 to 20 mass % of Cr and a predetermined amount of C, Si, Mn, P, S, Al and one or both of Ti and Nb, a {111}-orientation intensity being 5 or more and {411}-orientation intensity being less than 3 at a portion in the vicinity of a sheet-thickness central portion of the ferritic stainless steel sheet. Further, with similar composition and by setting {111}<110>-orientation intensity at 4.0 or more and {311}<136>-orientation intensity at less than 3.0, a relationship r.sub.m≧−1.0t+3.0 (t (mm): sheet thickness, r.sub.m: average r-value) is satisfied, thereby providing a ferritic stainless steel sheet and a steel pipe with excellent formability.
STEEL SHEET FOR CANS AND METHOD FOR MANUFACTURING STEEL SHEET FOR CANS
A steel sheet for cans has a chemical composition containing, by mass %, C: 0.015% or more and 0.150% or less, Si: 0.04% or less, Mn: 1.0% or more and 2.0% or less, P: 0.025% or less, S: 0.015% or less, Al: 0.01% or more and 0.10% or less, N: 0.0005% or more and less than 0.0050%, Ti: 0.003% or more and 0.015% or less, B: 0.0010% or more and 0.0040% or less, and the balance being Fe and inevitable impurities. The steel sheet has a microstructure including a ferrite phase as a main phase and at least one of a martensite phase and a retained austenite phase as a second phase, the total area fraction of the second phase being 1.0% or more, and the sheet has a tensile strength of 480 MPa or more, a total elongation of 12% or more, and a yield elongation of 2.0% or less.
Method for producing steel for blades
Disclosed is a method for producing steel for blades having a metal composition consisting of, by mass, 0.55% to 0.8% C, not more than 1.0% Si, not more than 1.0% Mn, 12.0% to 14.0% Cr, not more than 1.0% Mo, not more than 1.0% Ni, and the balance Fe with impurities, comprising: a batch annealing step for batch annealing a material to be cold rolled having the metal composition at a temperature of 500° C. to 700° C. for 3 to 30 hours; a continuous annealing step for continuously annealing the batch annealed material for 5 to 30 minutes so that the batch annealed material is heated to at least an Ac1 transformation point of the metal composition step to obtain a continuously annealed material; and a cold rolling step for cold rolling the continuously annealed material, wherein the continuous annealing step and the cold rolling step are performed at least once, respectively.
Stainless steel foil
According to aspects of the invention, provided are an Fe—Cr—Al-based stainless steel sheet which has improved manufacturability by improving the toughness of a hot-rolled steel sheet and a cold-rolled steel sheet without deteriorating oxidation resistance at a high temperature and shape stability when used at a high temperature, and a stainless steel foil which is manufactured by rolling the stainless steel sheet. V and B are added in combination to Fe—Cr—Al-based stainless steel in amounts within specified ranges. Specifically, V content is controlled to be 0.010% or more and 0.050% or less and B content is controlled to be 0.0001% or more and 0.0050% or less, in which the relationship {V content (V %)}/{B content (B %)}>10 is satisfied.
Ferrite-based stainless steel plate, steel pipe, and production method therefor
A ferritic stainless steel sheet and a steel pipe as a material suitable for a heat-resistant component that is required to have especially excellent formability are provided. The ferritic stainless steel sheet contains 10 to 20 mass % of Cr and a predetermined amount of C, Si, Mn, P, S, Al and one or both of Ti and Nb, a {111}-orientation intensity being 5 or more and {411}-orientation intensity being less than 3 at a portion in the vicinity of a sheet-thickness central portion of the ferritic stainless steel sheet. Further, with similar composition and by setting {111}<110>-orientation intensity at 4.0 or more and {311}<136>-orientation intensity at less than 3.0, a relationship r.sub.m≥−1.0t+3.0 (t(mm): sheet thickness, r.sub.m: average r-value) is satisfied, thereby providing a ferritic stainless steel sheet and a steel pipe with excellent formability.
ALUMINIUM ALLOY SHEET PRODUCT WITH IMPROVED SURFACE ASPECT
The invention relates to a rolled aluminum-based alloy product for cosmetic packaging comprising, (in weight %): Mn 1.0-1.5, Mg 0.2-0.6, Si 0.2-0.6, Fe 0.1-0.7, Cu 0.05-0.3, Cr 0-0.1, Zn 0-0.3, Ti 0-0.15, other elements ≤0.05 each and ≤0.15 total, remainder Al, wherein the fraction of Al(Fe,Mn)Si phase is at least 50%. The invention also related to a process for the manufacture of a rolled aluminum-based alloy product comprising the steps of: a) casting an ingot with a composition according to the invention; b) homogenizing the ingot at a temperature of at least 480° C.; c) hot rolling said homogenized ingot to a hot-rolled intermediate product; d) cold rolling said hot-rolled intermediate product to a cold-rolled intermediate product; e) recrystallization annealing of the cold-rolled intermediate product; f) cold rolling the annealed cold-rolled intermediate product to a cold-rolled product at final thickness; g) recovery annealing the cold-rolled product at final thickness. The products of the invention are particularly useful for cosmetic packaging, preferably for containers such as bottles, cups, tubes, holders, with a matt surface aspect.