Patent classifications
C21D7/13
High manganese steel for low temperature applications having excellent surface quality and a manufacturing method thereof
The present invention relates to a high manganese steel for low temperature applications and a method for manufacturing the same. The high manganese steel contains 0.3 wt % to 0.8 wt % of C, 18 wt % to 26 wt % of Mn, 0.01 wt % to 1 wt % of Si, 0.01 wt % to 0.5 wt % of Al, 0.1 wt % or less of Ti (excluding 0%), 1 wt % to 4.5 wt % of Cr, 0.1 wt % to 0.9 wt % of Cu, 0.03 wt % or less of S (excluding 0%), 0.3 wt % or less of P (excluding 0%), 0.001 wt % to 0.03 wt % of N, 0.004 wt % or less of B (excluding 0%), and a remainder of Fe and other inevitable impurities, wherein a microstructure comprises an austenite single phase structure, and an average grain size of the austenite is 50 μm or less.
Method for manufacturing a metal sheet with a ZnAl coating and with optimized wiping, corresponding metal sheet, part and vehicle
A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 μm.
Method for manufacturing a metal sheet with a ZnAl coating and with optimized wiping, corresponding metal sheet, part and vehicle
A steel part includes a steel sheet substrate and a coating on at least one surface of the steel sheet substrate. The coating includes between 0.2 and 0.7% by weight of Al, with a remainder of the metal coating being Zn and inevitable impurities. The steel sheet substrate and the coating have at least one deformation. An outer surface of the coating has a waviness Wa.sub.0.8 of less than or equal to 0.43 μm.
Steel with Controlled Yield Ratio and Manufacturing Method therefor
Disclosed are a steel with controlled steel ratio and a manufacturing method therefor. The steel comprises the following components in percentage by mass: C: 0.245-0.365%, Si: 0.10-0.80%, Mn: 0.20-2.00%, P:≤0.015%, S:≤0.003%, Cr: 0.20-2.50%, Mo: 0.10-0.90%, Nb: 0-0.08%, Ni: 2.30-4.20%, Cu: 0-0.30%, V: 0.01-0.13%, B: 0-0.0020%, Al: 0.01-0.06%, Ti: 0-0.05%, Ca:≤0.004%, H:≤0.0002%, N:≤0.013%, O:≤0.0020%, and the balance of Fe and inevitable impurities, wherein the components satisfy (8.57*C+1.12*Ni)≥4.8% and 1.2%≤(1.08*Mn+2.13*Cr)≤5.6%. The steel has excellent low-temperature impact toughness and aging impact toughness at −20° C. and −40° C., a rationally controlled yield ratio, and ultra-high strength, ultra-high toughness, and ultra-high plasticity, which can be used in applications such as offshore platform mooring chains, mechanical structures, and automobiles that require high strength and toughness of the steel.
HOT PRESSED MEMBER AND METHOD OF PRODUCING SAME, AND COATED STEEL SHEET FOR HOT PRESS FORMING
A hot pressed member disclosed herein includes: a base steel sheet; a Fe—Zn—Al—Mg-based alloy coated layer containing an α-Fe phase and a Γ phase and formed on at least one surface of the base steel sheet; and an oxide layer containing Zn, Al, and Mg and formed on the Fe—Zn—Al—Mg-based alloy coated layer, in which a ratio of I.sub.Γ/I.sub.α is 0.5 or less when measured by X-ray diffraction using a Co-Kα (wavelength: 1.79021 Å) radiation source at an incident angle of 25°, where IF is an intensity of a diffraction peak of (411) plane of the Γ phase present in an angular range of 41.5°≤2θ≤43.0° and I.sub.α is an intensity of a diffraction peak of (110) plane of the α-Fe phase present in an angular range of 51.0°≤2θ≤52.0°, and a sum of Al and Mg concentrations in the oxide layer is 28 atomic % or more.
STEEL SHEET FOR HOT STAMPING
This steel sheet for hot stamping includes a base material, an Al-Si alloy plating layer in which the Al content is 75 mass% or more, the Si content is 3 mass% or more and the total of the Al content and the Si content is 95 mass% or more and a Ni plating layer in which the Ni content is more than 90 mass% in this order, the chemical composition of the base material is, by mass%, C: 0.01% or more and less than 0.70%, Si: 0.005% to 1.000%, Mn: 0.40% to 3.00%, Nb: 0.010% to 0.200%, a solid solution of Nb: 0.010% to 0.150%, sol. A1: 0.00020% to 0.50000%, P: 0.100% or less, S: 0.1000% or less, N: 0.0100% or less, Cu: 0% to 1.00%, Ni: 0% to 1.00%, V: 0% to 1.00%, Ti: 0% to 0.150%, Mo: 0% to 1.000%, Cr: 0% to 1.000%, B: 0% to 0.0100%, Ca: 0% to 0.010%. REM: 0% to 0.300%, and a remainder: Fe and an impurity, the Al-Si alloy plating layer has a thickness of 7 to 148 .Math.m, and the Ni plating layer has a thickness of more than 200 nm and 2500 nm or less.
HOT-STAMPING FORMED BODY
This hot-stamping formed body has a predetermined chemical composition and has a metallographic structure consisting of, by area ratio, a total of 10% to 30% of ferrite and granular bainite and a remainder in microstructure consisting of one or more of martensite, bainite, and tempered martensite, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<−1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<−1-12> are controlled.
ADJUSTABLE SHIELD FOR LOCAL AUSTENITIZING
A shield covers a predetermined region of a plate workpiece during tempering of the plate workpiece in a furnace in which the shield and the workpiece are subjected to an austenitization temperature while the predetermined region of the plate is shielded by the shield against heat. The shield has at least one first shield part shaped to cover at least some of the predetermined region of the workpiece, at least one second shield part, and a fastener or the like securing the second part movably relative to or removable from the first part such that the first and second parts together achieve an optimum shape fully covering and shielding the predetermined region of the plate workpiece.
INTERMEDIATE HEATING STATION
A heating station (1) for heating a metal sheet blank (50) and a system comprising such a heating station (1), is herein disclosed. In particular, the heating station comprises lower or upper heating elements (11) arranged in a heating chamber (10) below a metal sheet blank (50) when in a heating position, and configured to provide radiation heating towards the metal sheet blank (50), and a lower mask (14) arranged to block radiation heating from reaching at least a first portion of the metal sheet blank (50), wherein the lower mask (14) comprises a plurality of support projections (14d) projecting from a main surface (14a) of the lower mask (14) towards the metal sheet blank (50) when in a heating position, which support projections (14d) are configured to support a metal sheet blank (50) during heating thereof.
INTERMEDIATE HEATING STATION
A heating station (1) for heating a metal sheet blank (50) and a system comprising such a heating station (1), is herein disclosed. In particular, the heating station comprises lower or upper heating elements (11) arranged in a heating chamber (10) below a metal sheet blank (50) when in a heating position, and configured to provide radiation heating towards the metal sheet blank (50), and a lower mask (14) arranged to block radiation heating from reaching at least a first portion of the metal sheet blank (50), wherein the lower mask (14) comprises a plurality of support projections (14d) projecting from a main surface (14a) of the lower mask (14) towards the metal sheet blank (50) when in a heating position, which support projections (14d) are configured to support a metal sheet blank (50) during heating thereof.