A method for producing a steel includes preparing a steel sheet having a chemical composition in % by mass of: C: 0.05 to 0.40%, Si: 0 to 2.0%, Mn: 1.0 to 3.0%, Al: 0.010 to 1.0%, P: more than 0% and 0.100% or less, S: more than 0% and 0.010% or less, N: more than 0% and 0.010% or less, B: 0.0005 to 0.010%, and iron; heating the steel sheet to Ac1 point (° C.) or higher and lower than Ac3 point (° C.)+10° C.; processing the steel sheet by applying a strain of 0.5% or more thereto at 675° C. or higher and lower than Ac3 point+10° C.; holding or gradually cooling the steel sheet at an average cooling rate of 0 to 15° C./sec for 1 second or more and 120 seconds or less; and cooling the steel sheet to Ms point (° C.)−50° C.

A method for producing a steel includes preparing a steel sheet having a chemical composition in % by mass of: C: 0.05 to 0.40%, Si: 0 to 2.0%, Mn: 1.0 to 3.0%, Al: 0.010 to 1.0%, P: more than 0% and 0.100% or less, S: more than 0% and 0.010% or less, N: more than 0% and 0.010% or less, B: 0.0005 to 0.010%, and iron; heating the steel sheet to Ac1 point (° C.) or higher and lower than Ac3 point (° C.)+10° C.; processing the steel sheet by applying a strain of 0.5% or more thereto at 675° C. or higher and lower than Ac3 point+10° C.; holding or gradually cooling the steel sheet at an average cooling rate of 0 to 15° C./sec for 1 second or more and 120 seconds or less; and cooling the steel sheet to Ms point (° C.)−50° C.

There is provided an austenitic heat resistant steel including a chemical composition that consists of, in mass %, C: 0.04 to 0.12%, Si: 0.01 to 0.30%, Mn: 0.50 to 1.50%, P: 0.001 to 0.040%, S: less than 0.0050%, Cu: 2.2 to 3.8%, Ni: 8.0 to 11.0%, Cr: 17.7 to 19.3%, Mo: 0.01 to 0.55%, Nb: 0.400 to 0.650%, B: 0.0010 to 0.0060%, N: 0.050 to 0.160%, Al: 0.025% or less, and O: 0.020% or less, with the balance: Fe and impurities and that satisfies [0.170≤Nb−Nb.sub.ER≤0.480].

There is provided an austenitic heat resistant steel including a chemical composition that consists of, in mass %, C: 0.04 to 0.12%, Si: 0.01 to 0.30%, Mn: 0.50 to 1.50%, P: 0.001 to 0.040%, S: less than 0.0050%, Cu: 2.2 to 3.8%, Ni: 8.0 to 11.0%, Cr: 17.7 to 19.3%, Mo: 0.01 to 0.55%, Nb: 0.400 to 0.650%, B: 0.0010 to 0.0060%, N: 0.050 to 0.160%, Al: 0.025% or less, and O: 0.020% or less, with the balance: Fe and impurities and that satisfies [0.170≤Nb−Nb.sub.ER≤0.480].

The hot-rolled coated steel sheet comprising: in wt %, C: 0.05-0.14%, Si: 0.1-1.0%, Mn: 1.0-2.0%, P: 0.001-0.05%, S: 0.001-0.01%, AI: 0.01-0.1%, Cr: 0.005-1.0%, Ti: 0.005-0.13%, Nb: 0.005-0.03%, N: 0.001-0.01%, Fe residues, and other inevitable impurities; a mixed structure of ferrite and bainite as a main phase; and as a remaining structure, one or more selected from the group consisting of martensite, austenite, and phase martensite (MA), wherein a fraction of the ferrite and bainite is 95-99 area % and Equation 1 is satisfied. [Equation 1] FCO.sub.{110}<112>+FCO.sub.{112}<111>≥10 where, FCO.sub.{110}<112> and FCO.sub.{112}<111>, each representing an area fraction occupied by a structure having ac crystal orientation of {110}<112> and {112}<111>.

The invention relates to an apparatus (1) for cooling an automobile component (20) by means of a gas, the apparatus comprising a cooling box (11) with a re-closeable opening (12) for receiving an automobile component (20) to be cooled, wherein at least one heat sink (13) is provided inside the cooling box (11) for cooling of the gas, and wherein the apparatus (10) includes at least one infra sound pulsator (2, 3) arranged to provide an infra sound into said cooling box (11) to improve heat exchange of the gas both with a cooling surface of the at least one heat sink (13), and with the automobile component (20). The invention also relates to a process for cooling an automobile component in such an apparatus.

The invention relates to an apparatus (1) for cooling an automobile component (20) by means of a gas, the apparatus comprising a cooling box (11) with a re-closeable opening (12) for receiving an automobile component (20) to be cooled, wherein at least one heat sink (13) is provided inside the cooling box (11) for cooling of the gas, and wherein the apparatus (10) includes at least one infra sound pulsator (2, 3) arranged to provide an infra sound into said cooling box (11) to improve heat exchange of the gas both with a cooling surface of the at least one heat sink (13), and with the automobile component (20). The invention also relates to a process for cooling an automobile component in such an apparatus.

A high strength cold rolled steel sheet having excellent burring properties includes: by weight %, 0.13-0.25% of carbon (C), 1.0-2.0% of silicon (Si), 1.5-3.0% of manganese (Mn), 0.08-1.5% of aluminum (Al)+chrome (Cr)+molybdenum (Mo), 0.1% or less of phosphorus (P), 0.01% or less of sulfur (S), 0.01% or less of nitrogen (N), and the balance of Fe and inevitable impurities; and, by area fraction, 3-25% of ferrite, 20-40% of martensite, 5-20% of residual austenite. The ferrite has an average grain size of 2 μm or less at the reference point of 4/t (wherein t refers to a steel sheet thickness), with the average ratio between lengths in the thickness direction and in the rolling direction being 1.5 or less.

An additive manufacturing system including a two-dimensional energy patterning system for imaging a powder bed is disclosed. The two-dimensional energy patterning system may be used to control the rate of cooling experienced by each successive additive layer. Accordingly, the system may be used to heat treat the various additive layers.

An additive manufacturing system including a two-dimensional energy patterning system for imaging a powder bed is disclosed. The two-dimensional energy patterning system may be used to control the rate of cooling experienced by each successive additive layer. Accordingly, the system may be used to heat treat the various additive layers.