摘要:
A manufacturing equipment for galvanized steel sheet includes coating tub to coat steel sheet dipped in coating bath wherein the bath including molten zinc and Al is stored at bath temperature T1, separating tub to separate by a flotation top-dross by precipitating the top-dross in the bath wherein the bath transferred from the coating tub is stored at bath temperature T2 lower than T1, adjusting tub to dissolve dross wherein the bath transferred from the separating tub is stored at bath temperature T3 higher than T2 and Fe of the bath is unsaturated, and circulator to circulate the bath in order of the coating tub, the separating tub, and the adjusting tub.
摘要:
A method of forming an Al—Zn—Si—Mg alloy coating on a steel strip includes dipping steel strip into a bath of molten Al—Zn—Si—Mg alloy and forming a coating of the alloy on exposed surfaces of the steel strip. The method also includes controlling conditions in the molten coating bath and downstream of the coating bath so that there is a uniform Al/Zn ratio across the surface of the coating formed on the steel strip. An Al—Zn—Mg—Si coated steel strip includes a uniform Al/Zn ratio on the surface or the outermost 1-2 μm of the Al—Zn—Si—Mg alloy coating.
摘要:
Certain methods enable the production of steel components with well-adhering metallic coatings that protect against corrosion. In some examples, a flat steel product produced from a steel material having a yield point of 150-1100 MPa and a tensile strength of 300-1200 MPa may be coated with an anticorrosion coating of an alloy that comprises 35-70% by weight aluminum, 35-60% by weight zinc, 0.1-10% by weight magnesium, up to 10% by weight Si, and up to 5% by weight Fe. A blank obtained from the flat steel product may then be heated to at least 800° C. and formed into a steel component. Alternatively, the steel component may be formed into the steel component first and then heated to at least 800° C. Regardless, the steel component may then be hardened by sufficiently rapid cooling the steel component from a sufficiently high temperature.
摘要:
The present invention provides a spot welded joint of at least two steel sheets. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≦C≦0.21%, 4.0≦Mn≦7.0%, 0.5≦Al≦3.5%, Si≦2.0%, Ti≦0.2%, V≦0.2%, Nb≦0.2%, P≦0.025%, B≦0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm2 and containing more than the steel nominal phosphorus content.
摘要:
The invention relates to the manufacture of a cold-rolled steel sheet having a strength of more than 900 MPa, an elastic limit of more than 700 MPa and distributed elongation of more than 12%, the composition of which includes, the contents being expressed as weight percentages: 0.26%≦C≦0.45%, 1.0%≦Mn≦3.0%, 1.0%≦Si≦3.0%, Al≦0.10%, 0%≦Cr≦1.5% %, S≦0.005%, P≦0.020%, Nb≦0.1%, Ti≦0.020%, V≦0.015%, N≦0.01%, the remainder of the composition being iron and inevitable impurities resulting from the production process. The microstructure, given in surface proportions, comprises 13% to 25% residual austenite and 13% to 30% MA islands, the remainder consisting of bainite and possibly ferrite.
摘要:
A method for hot dip coating a flat stainless steel product with more than 5 wt. % Cr with a protective metallic coating by: heating the flat steel product under an oxygen-free heating atmosphere to 100° C.-600° C. within 1-30 seconds; continuing heating to a holding temperature of 750° C.-950° C., by heating to 550° C.-800° C. under an inert or reducing atmosphere, holding within this temperature window for 1 to 15 seconds under an oxidizing atmosphere, and continuing heating under an inert or reducing atmosphere, until the holding temperature is reached; holding at the holding temperature for 10-120 seconds under a reducing atmosphere; and passing the flat steel product through a nozzle area under an inert or reducing atmosphere at 430°-780° C. and into a molten bath in which the flat steel product is coated with the metallic coating.
摘要:
The invention relates to a method for the production of carbon fibre reinforced aluminium matrix composite wires by drawing carbon fibres through molten salt and molten aluminium in such a way that the molten aluminium and the molten salt are spatially separated, and the carbon fibres are drawn through first the molten salt, then the molten aluminium separated from it. The invention further relates to an apparatus for the implementation of the method.
摘要:
A hot-stamped steel according to the present invention has a predetermined chemical composition, satisfies (5×[Si]+[Mn])/[C]>10 when [C] is the amount of C by mass %, [Si] is the amount of Si by mass %, and [Mn] is the amount of Mn by mass %, includes 40% to 95% ferrite and 5% to 60% martensite in area fraction, and optionally further includes 10% or less pearlite in area fraction, 5% or less retained austenite in volume fraction, and less than 40% bainite in area fraction. The total of the area fraction of ferrite and the area fraction of martensite is 60% or more, the hardness of martensite measured with a nanoindenter satisfies H2/H1
摘要:
A method for improving the weldability of hot stamping parts improving weldability of hot stamping parts with degraded weldability due to surface oxides is provided.In accordance with an embodiment of the present invention, a method for improving the weldability of hot stamping parts comprises: selecting a welding region in a hot stamping part; removing surface oxide of the welding region; and performing welding on a welding region on a hot stamping part with surface oxide removed.
摘要:
A method of forming a steel part is provided. The method includes the steps of coating a first steel plate to obtain a first precoat upon the first steel plate so as to define a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer. On a first face of the first steel plate the first metal alloy layer is removed in a first area of the first steel plate, while at least part of the first intermetallic alloy layer in the first area remains. A second steel plate is coated to obtain a second precoat upon the second steel plate so as to define a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer. On a second face of the second steel plate, the second metal alloy layer is removed in a second area of the second metal plate, while at least part of the second intermetallic alloy layer in the second area remains. After removal of the first and second metal alloy layers, the first steel plate is butt-welded to the second steel plate at the first and second areas to form a welded blank. A heat treatment is performed on the welded blank. The welded blank is shaped after the heat treatment into the steel part. A steel part is also provided.