Patent classifications
C21D9/0081
ENDLESS ROLLING METHOD BASED ON TEMPERATURE UNIFORMITY CONTROL
The invention provides an endless rolling method based on temperature uniformity control, and belongs to the field of iron and steel metallurgy. By optimizing the process path, a new layout mode is adopted, a double heat storage soaking furnace and a descaling box are additionally arranged, transverse and longitudinal bonding magnetic induction heating device is adopted, transverse and longitudinal temperature uniform of the slab in the rolling process is realized, the cross section temperature difference is reduced, and the product quality is improved. On the basis of five-stand arrangement of a traditional finish rolling mill, a rolling mill is additionally arranged to serve as a standby rolling mill, such that on-line non-shutdown change roller of the finish rolling mill is realized. The method of the invention realizes a full-continuous production of production and meets the high-quality development requirements of iron and steel metallurgy, such that traditional cool rolling can be replaced with hot rolling, traditional thick-specification strip can be replaced with high-added-value thin specification strip. There is important significance in the aspects of productivity optimization layout, green manufacturing, intelligent manufacturing and the like.
ORIENTED ELECTRICAL STEEL SHEET AND METHOD FOR PREPARING SAME
An oriented electrical steel sheet according to an embodiment of the present invention includes, in a unit of wt %, Si at 1.0 wt % to 5.0 wt %, C at 0.005 wt % or less (excluding 0 wt %), Mn at 0.001 wt % to 0.1 wt %, Cu at 0.001 wt % to 0.1 wt %, S at 0.001 wt % to 0.020 wt %, Se at 0.001 wt % to 0.050 wt %, Al at 0.0005 wt % to 0.010 wt %, N at 0.0005 wt % to 0.005 wt %, and the remainder of Fe and inevitable impurities.
The oriented electrical steel sheet according to the embodiment of the present invention satisfies Equation 1.
16≤(10×[Mn]+[Cu])/([S]+[Se])+(0.02−[Al])/[N]≤20 [Equation 1]
(In Equation 1, [Mn], [Cu], [S], [Se], [Al], and [N] represent contents (wt %) of Mn, Cu, S, Se, Al, and N, respectively.)
HIGH STRENGTH STEEL PRODUCT AND METHOD OF MANUFACTURING THE SAME
A hot-rolled strip steel product is described having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.030%-0.10% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.010% S,<0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.30% Mo, 0%-0.15% Al, 0%-0.10% Nb, 0.10%-0.30% V, <0.020% Ti, 0%-0.0010% B, remainder being Fe and inevitable impurities, wherein the hot rolled strip steel product has a a microstructure comprising, in terms of volume percentages (vol. %), ferrite≥90, wherein the ferrite structure comprises bainite, at least 50% of polygonal ferrite and at most 10% quasi-polygonal ferrite, and wherein the steel strip product has an average hole expansion ratio≥50%, a yield strength (Rp0.2%) longitudinal to rolling direction of ≥660 MPa and a tensile strength≥760 MPa.
STEEL FOR MINING CHAIN AND MANUFACTURING METHOD THEREOF
A steel for mining chain and a manufacturing method thereof, wherein the steel has compositions by weight percentage: C: 0.20-0.28%, Si: 0.01-0.40%, Mn: 0.50-1.50%, P≤0.015%, S≤0.005%, Cr: 0.30-2.00%, Ni: 0.50-2.00%, Mo: 0.10-0.80%, Cu: 0.01-0.30%, Al: 0.01-0.05%, Nb: 0.001-0.10%, V: 0.001-0.10%, H≤0.00018%, N≤0.0150%, O≤0.0020%, and the balance is Fe and inevitable impurities. The manufacturing method comprises steps of smelting, refining and vacuum treatment, casting, heating, forging or rolling, and quenching and tempering heat treatment processes. The steel in the present invention has high strength and good impact toughness, good elongation and reduction of area. The steel can also resist stress corrosion cracking and have good weather resistance, wear resistance and fatigue resistance, which can be used in scenarios where the steel having high strength and toughness is required, such as construction machinery and marine engineering.
TIN BLACKPLATE FOR PROCESSING AND METHOD FOR MANUFACTURING SAME
The present invention provides a tin blackplate for processing and a method for manufacturing the same.
The tin blackplate according to an exemplary embodiment of the present invention comprises: in % by weight, 0.0005 to 0.005% of carbon (C), 0.15 to 0.60% of manganese (Mn), 0.01 to 0.06% of aluminum (AI), 0.0005 to 0.004% of nitrogen (N), 0.0005 to 0.003% of boron (B), 0.01 to 0.035% of titanium (Ti), and the balance being iron (Fe) and inevitable impurities, and satisfies the following Formula 1.
4.8≤([Ti]+[Al])/[N]−[B]≤12.5 [Equation 1]
In this case, in Equation 1, [Ti], [Al], [N], and [B] mean each value obtained by dividing the content (% by weight) of Ti, Al, N, and B in the blackplate by each atomic weight thereof.
Duplex ferritic austenitic stainless steel
Disclosed is a duplex ferritic austenitic stainless steel of 40-60 volume % ferrite and 40-60 volume % austenite, with improved cold workability and impact toughness. It contains less than 0.07% carbon (C), 0.1-2.0% silicon (Si), 3-5% manganese (Mn), 19-23% chromium (Cr), 1.1-1.9% nickel (Ni), 1.1-3.5% copper (Cu), 0.18-0.30% nitrogen (N), optionally molybdenum (Mo) and/or tungsten (W) according to the formula (Mo+½W)<1.0%. It optionally contains 0.001-0.005% boron (B), up to 0.03% of each of cerium (Ce) and/or calcium (Ca), with the balance being iron (Fe) and impurities where the chromium equivalent (Cr.sub.eq) and the nickel equivalent (Ni.sub.eq): 20<Cr.sub.eq<24.5 and Ni.sub.eq>10, where Cr.sub.eq=Cr+1.5Si+Mo+2Ti+0.5Nb Ni.sub.eq=Ni+0.5Mn+30(C+N)+0.5(Cu+Co).
ULTRAHIGH-STRENGTH DUAL-PHASE STEEL AND MANUFACTURING METHOD THEREFOR
Disclosed in the present disclosure is an ultrahigh-strength dual-phase steel. The matrix structure of the ultrahigh-strength dual-phase steel is ferrite and martensite, wherein the ferrite and the martensite are evenly distributed in an island shape. The ultrahigh-strength dual-phase steel contains the following chemical elements in percentage by mass: 0.12-0.2% of C, 0.5-1.0% of Si, 2.5-3.0% of Mn, 0.02-0.05% of Al, 0.02-0.05% of Nb, 0.02-0.05% of Ti, and 0.001-0.003% of B. Further disclosed in the present disclosure is a manufacturing method for the ultrahigh-strength dual-phase steel, comprising the steps of smelting and continuous casting, hot rolling, cold rolling, annealing, tempering, and leveling. The ultrahigh-strength dual-phase steel in the present disclosure has not only good mechanical properties but also excellent delayed cracking resistance and low initial hydrogen content, and can be suitable for manufacturing of vehicle safety structural parts.
HIGH-STRENGTH BLACKPLATE AND MANUFACTURING METHOD THEREFOR
The present invention provides a high-strength tin blackplate and a manufacturing method therefor.
The tin blackplate according to an exemplary embodiment of the present invention includes: by wt %, 0.03 to 0.09% of carbon (C); 0.2 to 0.4% of manganese (Mn); 0.01 to 0.06% of aluminum (Al); 0.15 to 0.45% of chromium (Cr); 0.05 to 0.25% of copper (Cu); 0.03 to 0.08% of titanium (Ti); and the balance of iron (Fe) and inevitable impurities, and has a yield strength of 570 to 700 MPa.
Wrought magnesium alloy having improved properties, method of manufacturing same, and high-speed extrusion method using same
This application relates to a wrought magnesium alloy and a method of manufacturing the same, and a high-speed extrusion method for manufacturing an extrudate using the same. In one aspect, the magnesium alloy includes 2.0 wt % to 8.0 wt % of bismuth (Bi), 0.5 wt % to 6.5 wt % aluminum (Al), the balance of magnesium (Mg), and inevitable impurities. Using a magnesium alloy for high-speed extrusion according to the present disclosure, it is possible to manufacture a magnesium alloy extrudate having a good surface quality without hot cracking even under high-temperature (extrusion temperature: 300° C. to 450° C.) and high-speed (die-exit speed: 40 m/min to 80 m/min) extrusion conditions. Furthermore, the extrudate manufactured from the magnesium alloy exhibits greatly improved strength and elongation compared to existing magnesium extrudates even when the alloy does not contain a rare-earth metal.
Austenitic stainless steel having excellent processability and surface characteristics, and manufacturing method therefor
An austenitic stainless steel having excellent processability and surface characteristics and a method of manufacturing the austenitic stainless steel are disclosed. The austenitic stainless steel includes, by weight %, 0.005% to 0.15% of carbon (C), 0.1% to 1.0% of silicon (Si), 0.1% to 2.0% of manganese (Mn), 6.0% to 10.5% of nickel (Ni), 16% to 20% of chromium (Cr), 0.005% to 0.2% of nitrogen (N), the remainder iron (Fe) and other unavoidable impurities, wherein a degree of Ni surface negative segregation defined by the following Formula (1) is in a range of 0.6 to 0.9.
(C.sub.Ni-Min)/(C.sub.Ni-Ave) Formula (1), where C.sub.Ni-Min is a minimum concentration of Ni on the surface of the austenitic stainless steel and C.sub.Ni-Ave is an average concentration of Ni on the surface of the austenitic stainless steel.