Abstract: A hot-dip galvanized steel sheet includes a base steel sheet and a hot-dip galvanized layer formed on the base steel sheet, the base steel sheet including, by wt %, C: 0.02% to 0.08%, Mn: 1.3% to 2.1%, Si: 0.3% or less (excluding 0%), Cr: 1.0% or less (excluding 0%), P: 0.1% or less (excluding 0%), S: 0.01% or less (excluding 0%), N: 0.01% or less (excluding 0%), sol.Al: 0.02% to 0.06%, Mo: 0.2% or less (excluding 0%), B: 0.003% or less (excluding 0%), and a balance of Fe and inevitable impurities, wherein the base steel sheet has a microstructure comprising 90% or more by area of ferrite, 3% or less by area of bainite as described in Formula 1, and martensite as a remainder.

Abstract: There is provided a hot-dip galvanized steel sheet and a hot-dip galvannealed steel sheet, which have excellent elongation properties, and methods for manufacturing the hot-dip galvanized steel sheet and the hot-dip galvannealed steel sheet. The present disclosure relates to a hot-dip galvanized steel sheet in which a hot-dip galvanized layer is formed on a surface of a base steel sheet, the hot-dip galvanized steel sheet having excellent elongation properties and being characterized by the composition and the microstructure thereof.

Abstract: Provided are a bake hardening steel having a crystalline grain size of ASTM No. 9 or more and a method for preparing the bake hardening steel by controlling the winding, rolling and cooling conditions. The bake hardening steel includes: C:0.0016˜0.0025%, Si:0.02% or less, P:0.01˜0.05%, S:0.01% or less, sol.Al:0.08˜0.12%, N:0.0025% or less, Ti:0.003% or less, Nb:0.003˜0.011%, Mo:0.01˜0.1%, B:0.0005˜0.0015% or less, balance Fe and other inevitable impurities, wherein % is weight %, and Mn and P satisfy the relation of ?30(° C.)?803P?24.4Mn?58.

Abstract: It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing. The cold-rolled steel sheet and the galvannealed steel sheet produced using the cold-rolled steel sheet have the superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance.

Abstract: Disclosed is a heavyweight concrete composition using slag byproducts, including: ground granulated blast furnace slag; slow-cooled electric-arc-furnace oxidizing slag or atomized steel slag used as a fine aggregate; a coarse aggregate; water; and a chemical admixture based on 100 parts by weight high-early-strength cement. Thus, the heavyweight concrete composition contains a large quantity of steel slag and blast-furnace slag that are byproducts in iron-making and steel-making processes, thereby remarkably reducing an amount of emission of carbon dioxide and maximizing the recycling of waste resources for preserving the natural environment. As a result, an eco-friendly heavyweight concrete product can be made.

Abstract: It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing. The cold-rolled steel sheet and the galvannealed steel sheet produced using the cold-rolled steel sheet have the superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance.

Abstract: Disclosed is a heavyweight concrete composition using slag byproducts, including: ground granulated blast furnace slag; slow-cooled electric-arc-furnace oxidizing slag or atomized steel slag used as a fine aggregate; a coarse aggregate; water; and a chemical admixture based on 100 parts by weight high-early-strength cement. Thus, the heavyweight concrete composition contains a large quantity of steel slag and blast-furnace slag that are byproducts in iron-making and steel-making processes, thereby remarkably reducing an amount of emission of carbon dioxide and maximizing the recycling of waste resources for preserving the natural environment. As a result, an eco-friendly heavyweight concrete product can be made.

Abstract: A cold-rolled steel sheet for outer panels and the like of an automobile body, a galvannealed steel sheet using the cold-rolled steel sheet, and a method for manufacturing the same are disclosed. It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing.

Abstract: Disclosed is a method for forming a conversion coating on the outer surface of magnesium or a magnesium alloy by surface treatment with acidic and alkaline solutions. The method is carried out in an environmentally friendly manner to improve the corrosion resistance of the magnesium or magnesium alloy. The method minimizes the damage to the appearance of the magnesium or magnesium even after surface treatment and maximizes the attractive appearance of the magnesium or magnesium alloy.

Abstract: Disclosed herein is a method for the surface treatment of magnesium or a magnesium alloy by anodization to form an anodized oxide coating on the magnesium or magnesium alloy. The method comprises: removing impurities and an oxide layer present on the surface of magnesium or a magnesium alloy using a strongly alkaline aqueous solution (pretreatment); and immersing the pretreated magnesium or magnesium alloy in an alkaline electrolyte and applying a direct current having a current density of 3 A/dm2 or less to the electrolyte to form a magnesium oxide coating (microarc plasma anodization).

Abstract: Provided are a bake hardening steel having a crystalline grain size of ASTM No. 9 or more and a method for preparing the bake hardening steel by controlling the winding, rolling and cooling conditions. The bake hardening steel includes: C:0.0016˜0.0025%, Si:0.02% or less, P:0.01˜0.05%, S:0.01% or less, sol.Al:0.08˜0.12%, N:0.0025% or less, Ti:0.003% or less, Nb:0.003˜0.011%, Mo:0.01˜0.1%, B:0.0005˜0.0015% or less, balance Fe and other inevitable impurities, wherein % is weight %, and Mn and P satisfy the relation of ?30(° C.)?803P?24.4Mn?58.

Abstract: A bake-hardenable high-strength cold-rolled steel sheet, a hot-dipped steel sheet thereof, and a method for manufacturing the same. The steel sheet comprises 0.0016˜0.01% of C; 0.1% or less of Si; 0.2˜1.5% of Mn; 0.05˜0.15% of P; 0.01% or less of S; 0.08˜0.5% of (soluble) Al; 0.0025% or less of N; 0.003˜0.1% of Nb; 0.003% or less of Ti; 0.01˜0.4% of Mo; 0.0005˜0.005% of B; and the balance of Fe and other unavoidable impurities, in terms of weight %. The method includes the steps of heating a steel slab of the above composition to a temperature of 1,200° C. or more; and then hot rolling the steel slab with finish rolling at or above the Ar3 temperature to provide a hot rolled steel sheet; coiling the hot rolled steel sheet; cold rolling the hot rolled and coiled sheet; and continuous annealing the cold rolled sheet.

Abstract: A bake-hardenable cold rolled steel sheet with high strength and superior aging resistance used for outer panels of an automobile body, a galvannealed steel sheet using the cold-rolled steel sheet, and a method for manufacturing the cold-rolled steel sheet are disclosed. The steel sheet comprises, by weight %, C: 0.0016˜0.0025%, Si: 0.02% or less, Mn: 0.2˜1.2%, P: 0.05˜0.11%, S: 0.01% or less, Sol. Al: 0.08˜0.12%, N: 0.0025% or less, Ti: 0˜0.003%, Nb: 0.003˜0.011%, Mo: 0.01˜0.1%, B: 0.0005˜0.0015%, the balance of Fe and other unavoidable impurities. The steel sheet has superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance.

Abstract: A cold-rolled steel sheet for outer panels and the like of an automobile body, a galvannealed steel sheet using the cold-rolled steel sheet, and a method for manufacturing the same are disclosed. It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing.

Abstract: Disclosed herein are a bake-hardenable high-strength cold-rolled steel sheet, a hot-dipped steel sheet thereof, and a method for manufacturing the same. The steel sheet comprises 0.0016˜0.01% of C; 0.1% or less of Si; 0.2˜1.5% of Mn; 0.05˜0.15% of P; 0.01% or less of S; 0.08˜0.5% of (soluble) Al; 0.0025% or less of N; 0.003˜0.1% of Nb; 0.003% of less of Ti; 0.01˜0.4% of Mo; 0.0005˜0.005% of B; and the balance of Fe and other unavoidable impurities, in terms of weight %. The steel sheet has fine AlN precipitates, and a grain size (ASTM No.) of 9 or more. The AlN precipitates have a grain size, which can suppress grain growth. The steel sheet has enhanced strength, bake hardenability, aging resistance, and secondary work embrittlement resistance.

Abstract: A separable distribution rotor and a horizontal rotor distributor having the same. The separable distribution rotor includes a first distribution rotor, a second distribution rotor, and an elastic member interposed between the first distribution rotor and the second distribution rotor.

Abstract: A separable distribution rotor and a horizontal rotor distributor having the same. The separable distribution rotor includes a first distribution rotor, a second distribution rotor, and an elastic member interposed between the first distribution rotor and the second distribution rotor.