Abstract: Improved steel compositions and methods of making the same are provided. The present disclosure provides advantageous wear resistant steel. More particularly, the present disclosure provides high manganese (Mn) steel having enhanced wear resistance, and methods for fabricating high manganese steel compositions having enhanced wear resistance. The advantageous steel compositions/components of the present disclosure improve one or more of the following properties: wear resistance, ductility, crack resistance, erosion resistance, fatigue life, surface hardness, stress corrosion resistance, fatigue resistance, and/or environmental cracking resistance. In general, the present disclosure provides high manganese steels tailored to resist wear and/or erosion.

Abstract: According to an exemplary embodiment of the present invention, a manufacturing method of a magnesium alloy plate includes: (a) solution-treating a magnesium casting material containing 0.5 to 10 wt % of zinc (Zn), 1 to 15 wt % of aluminum (Al), and a balance of magnesium (Mg) and inevitable impurities at 300 to 500° C. for 1 to 48 hours; (b) pre-heating the solution-treated magnesium casting material at 300 to 500° C.; and (c) of rolling the pre-heated magnesium casting material together with a constraint member selected by following Relational Expression 1 to satisfy Relational Expressions 2 and 3; and (d) solution-treating a thus-rolled magnesium alloy plate at 300 to 500° C. for 0.5 to 5 hours. Relational Expressions 1 to 3 are as described in the specification.

Abstract: An ultrahigh strength cold-rolled steel sheet and a manufacturing method thereof are provided. An ultrahigh strength cold-rolled steel sheet, according to a preferred aspect of the present invention, comprises, in percentage by weight: C: 0.25 to 0.4%; Si: 0.5% or less (excluding 0); Mn: 3.0 to 4.0%; P: 0.03% or less (excluding 0); S: 0.015% or less (excluding 0); Al: 0.1% or less; Cr: 1% or less (excluding 0); Ti: 48/14*[N] to 0.1% or less; Nb: 0.1% or less (excluding 0); B: 0.005% or less (excluding 0); N: 0.01% or less (excluding 0); and a balance of Fe and unavoidable impurities, and a microstructure includes 90% or more(including 100%) of martensite, and one or two kinds of 10% or less (including 0%) of ferrite and bainite.

Abstract: According to an exemplary embodiment of the present invention, a manufacturing method of a magnesium alloy plate includes: (a) solution-treating a magnesium casting material containing 0.5 to 10 wt % of zinc (Zn), 1 to 15 wt % of aluminum (Al), and a balance of magnesium (Mg) and inevitable impurities at 300 to 500° C. for 1 to 48 hours; (b) pre-heating the solution-treated magnesium casting material at 300 to 500° C.; and (c) of rolling the pre-heated magnesium casting material together with a constraint member selected by following Relational Expression 1 to satisfy Relational Expressions 2 and 3; and (d) solution-treating a thus-rolled magnesium alloy plate at 300 to 500° C. for 0.5 to 5 hours. Relational Expressions 1 to 3 are as described in the specification.

Abstract: Provided are an austenitic steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone including 15 wt % to 35 wt % of manganese (Mn), carbon (C) satisfying 23.6C+Mn?28 and 33.5C?Mn?23, 5 wt % or less (excluding 0 wt %) of copper (Cu), chromium (Cr) satisfying 28.5C+4.4Cr?57 (excluding 0 wt %), and iron (Fe) as well as other unavoidable impurities as a remainder, wherein a Charpy impact value of a weld heat-affected zone at ?196° C. is 41 J or more, and a method of manufacturing the steel. According to the present invention, a low-cost ultra-low temperature steel may be obtained, a stable austenite phase may be formed at low temperature, carbide formation may be effectively suppressed, and a structural steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone may be provided.

Abstract: Provided is a steel having excellent weldability and impact toughness in a welding zone comprising: by weight (wt.) %, carbon (C): 0.1% to 0.3%, manganese (Mn): 11% to 13%, iron (Fe) as a residual component thereof, and other inevitable impurities, and positive and negative segregation zones in a layered form. The positive segregation zone comprises austenite and epsilon martensite, and the negative segregation zone comprises, by area fraction, epsilon martensite of less than 5% and alpha martensite.

Abstract: Improved steel compositions and methods of making the same are provided. The present disclosure provides advantageous wear resistant steel. More particularly, the present disclosure provides high manganese (Mn) steel having enhanced wear resistance, and methods for fabricating high manganese steel compositions having enhanced wear resistance. The advantageous steel compositions/components of the present disclosure improve one or more of the following properties: wear resistance, ductility, crack resistance, erosion resistance, fatigue life, surface hardness, stress corrosion resistance, fatigue resistance, and/or environmental cracking resistance. In general, the present disclosure provides high manganese steels tailored to resist wear and/or erosion.

Abstract: The present invention relates to a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone and a preparation method therefor. One embodiment of the present invention provides: a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone, comprising 0.8-1.5 wt % of C, 15-22 wt % of Mn, 5 wt % or less of Cr (except 0), and the balance of Fe and other inevitable impurities, and further comprising at least one of the following (a) and (b), wherein the microstructure of a welding heat-affected zone comprises 90% or more of austenite by volume fraction; and a preparation method therefor. (a) Mo: 0.1-1% and B: 0.001-0.02% (b) Ti: 0.01-0.3% and N: 0.003-0.1%.

Abstract: A high-manganese wear-resistant steel having excellent weldability comprises 5 to 15 wt % of Mn, 16?33.5C+Mn?30 of C, 0.05 to 1.0 wt % of Si, and a balance of Fe and other inevitable impurities. The microstructure thereof includes martensite as a major component, and 5% to 40% of residual austenite by area fraction.

Abstract: Provided is a steel sheet for low-temperature service, which can be used at a wide temperature range from low temperature to room temperature in liquefied gas storage tanks and transport facilities. The steel sheet for low-temperature service has an excellent surface processing quality even after a processing processes is performed, such as a tension process. The a steel sheet contains manganese (Mn, 15-35 wt %), carbon (C, satisfying 23.6C+Mn?28 and 33.5C—Mn?23), copper (Cu, 5 wt % or less (excluding 0 wt %)), chrome (Cr, satisfying 28.5C+4.4Cr?57 (excluding 0 wt %)), titanium (Ti, 0.01-0.5 wt %), nitrogen (N, 0.003-0.2 wt %), the balance iron (Fe), and other inevitable impurities. Ti and N satisfy relational expression 1 below. [Relational expression 1] 1.0?Ti/N?4.5 (Mn, C, Cr, Ti, and N in the respective expressions mean wt % of respective ingredient contents).

Abstract: There are provided an expandable high-strength steel material and an expanded high-strength steel pipe having excellent expandability and collapse resistance, and methods for manufacturing the expandable high-strength steel material and the expanded high-strength steel pipe. The expandable high-strength steel material including, by weight, manganese (Mn): 12% to 18%, carbon (C): 0.3% to 0.6%, and a balance of iron (Fe) and inevitable impurities, wherein the carbon (C) and the manganese (Mn) satisfy the following condition: 23?35.5C+Mn?38. Before being expanded, the expandable high-strength steel material has an austenite single phase microstructure, and after being expanded, the expandable high-strength steel material has a microstructure including 5 area % to 50 area % martensite and 50 area % to 95 area % austenite.

Abstract: There are provided a wear resistant austenitic steel having superior machinability and toughness in weld heat affected zones and a method for producing the austenitic steel. The austenitic steel includes, by weight %, manganese (Mn): 15% to 25%, carbon (C): 0.8% to 1.8%, copper (Cu) satisfying 0.7C-0.56(%)?Cu?5%, and the balance of iron (Fe) and inevitable impurities, wherein the weld heat affected zones have a Charpy impact value of 100 J or greater at ?40° C. The toughness of the austenitic steel is not decreased in weld heat affected zones because the formation of carbides during welding is suppressed, and the machinability of the austenitic steel is improved so that a cutting process may be easily performed on the austenitic steel. The corrosion resistance of the austenitic steel is improved so that the austenitic steel may be used for an extended period of time in corrosive environments.

Abstract: Steel for low-temperature service having a high degree of surface processing quality comprises: manganese (Mn): 15 wt % to 35 wt %, carbon (C) satisfying conditions of: 23.6C+Mn?28 and 33.5C?Mn?23, copper (Cu): 5 wt % or less (excluding 0 wt %), nitrogen (N): 1 wt % or less (excluding 0 wt %), chromium (Cr) satisfying a condition of: 28.5C+4.4Cr?57, nickel (Ni): 5 wt % or less, molybdenum (Mo): 5 wt % or less, silicon (Si): 4 wt % or less, aluminum (Al): 5 wt % or less, and a balance of iron (Fe) and inevitable impurities. Stacking fault energy (SFE) of the steel is 24 mJ/m2 or greater. The SFE is calculated by a formula: SFE (mJ/m2)=1.6Ni?1.3Mn+0.06Mn2?1.7Cr+0.01Cr2+15Mo?5.6Si+1.6Cu+5.5Al?60(C+1.2N)1/2+26.3(C+1.2N)(Cr+Mn+Mo)1/2+0.6[Ni(Cr+Mn)]1/2.

Abstract: Provided is a steel having excellent weldability and impact toughness in a welding zone comprising: by weight (wt.) %, carbon (C): 0.1% to 0.3%, manganese (Mn): 11% to 13%, iron (Fe) as a residual component thereof, and other inevitable impurities, and positive and negative segregation zones in a layered form. The positive segregation zone comprises austenite and epsilon martensite, and the negative segregation zone comprises, by area fraction, epsilon martensite of less than 5% and alpha martensite.

Abstract: According to one aspect, provided is a high-strength steel sheet having superior toughness at cryogenic temperature, comprising, in weight percentage, 0.02 to 0.06% of C, 0.1 to 0.35% of Si, 1.0 to 1.6% of Mn, 0.02% or less (but not 0%) of Al, 0.7 to 2.0% of Ni, 0.4 to 0.9% of Cu, 0.003 to 0.015% of Ti, 0.003 to 0.02% of Nb, 0.01% or less of P, 0.005% or less of S, the remainder being Fe and unavoidable impurities, wherein the high-strength steel sheet satisfies the condition of [Mn]+5.4[Si]+26[Al]+32.8[Nb]<4.3 where [Mn], [Si], [Al], and [Nb] indicate contents of Mn, Si, Al, and Nb in weight percentage, respectively. The steel sheet secures toughness when used as structural steel materials for ships, offshore structures, or the like, or steel materials for tanks for storing and carrying liquefied gases, which are exposed to an extreme low temperature environment.

Abstract: The present invention relates to a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone and a preparation method therefor. One embodiment of the present invention provides: a high strength austenitic-based steel with remarkable toughness of a welding heat-affected zone, comprising 0.8-1.5 wt % of C, 15-22 wt % of Mn, 5 wt % or less of Cr (except 0), and the balance of Fe and other inevitable impurities, and further comprising at least one of the following (a) and (b), wherein the microstructure of a welding heat-affected zone comprises 90% or more of austenite by volume fraction; and a preparation method therefor. (a) Mo: 0.1-1% and B: 0.001-0.02% (b) Ti: 0.01-0.3% and N: 0.003-0.

Abstract: A high-manganese wear-resistant steel having excellent weldability comprises 5 to 15 wt % of Mn, 16?33.5C+Mn?30 of C, 0.05 to 1.0 wt % of Si, and a balance of Fe and other inevitable impurities. The microstructure thereof includes martensite as a major component, and 5% to 40% of residual austenite by area fraction.

Abstract: Provided are an austenitic steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone including 15 wt % to 35 wt % of manganese (Mn), carbon (C) satisfying 23.6C+Mn?28 and 33.5C?Mn?23, 5 wt % or less (excluding 0 wt %) of copper (Cu), chromium (Cr) satisfying 28.5C+4.4Cr?57 (excluding 0 wt %), and iron (Fe) as well as other unavoidable impurities as a remainder, wherein a Charpy impact value of a weld heat-affected zone at ?196° C. is 41 J or more, and a method of manufacturing the steel. According to the present invention, a low-cost ultra-low temperature steel may be obtained, a stable austenite phase may be formed at low temperature, carbide formation may be effectively suppressed, and a structural steel having excellent machinability and ultra-low temperature toughness in a weld heat-affected zone may be provided.

Abstract: There are provided a wear resistant austenitic steel having superior machinability and toughness in weld heat affected zones and a method for producing the austenitic steel. The austenitic steel includes, by weight %, manganese (Mn): 15% to 25%, carbon (C): 0.8% to 1.8%, copper (Cu) satisfying 0.7C-0.56(%)?Cu?5%, and the balance of iron (Fe) and inevitable impurities, wherein the weld heat affected zones have a Charpy impact value of 100 J or greater at ?40° C. The toughness of the austenitic steel is not decreased in weld heat affected zones because the formation of carbides during welding is suppressed, and the machinability of the austenitic steel is improved so that a cutting process may be easily performed on the austenitic steel. The corrosion resistance of the austenitic steel is improved so that the austenitic steel may be used for an extended period of time in corrosive environments.

Abstract: There are provided a wear resistant austenitic steel having superior machinability and toughness in weld heat affected zones and a method for producing the austenitic steel. The austenitic steel includes, by weight %, manganese (Mn): 15% to 25%, carbon (C): 0.8% to 1.8%, copper (Cu) satisfying 0.7C-0.56(%)?Cu?5%, and the balance of iron (Fe) and inevitable impurities, wherein the weld heat affected zones have a Charpy impact value of 100 J or greater at ?40° C. The toughness of the austenitic steel is not decreased in weld heat affected zones because the formation of carbides during welding is suppressed, and the machinability of the austenitic steel is improved so that a cutting process may be easily performed on the austenitic steel. The corrosion resistance of the austenitic steel is improved so that the austenitic steel may be used for an extended period of time in corrosive environments.