STEEL MATERIAL HAVING EXCELLENT WEAR RESISTANCE AND MANUFACTURING METHOD
The purpose of the present invention is to provide a steel material and a manufacturing method for the same, wherein the steel material has excellent strength, elongation, and impact toughness as well as excellent inside quality and wear resistance. According to the present invention, provided are a steel material having excellent wear resistance and a manufacturing method for the same, wherein. the steel material contains, in weight, 0.55-1.4% carbon (C), 12-23% manganese (Mn), 5% or less (excluding 0%) chromium (Cr), 5% or less (excluding 0%) copper (Cu), 0.5% or less (excluding 0%) Al, 1.0% or less (excluding 0%) Si, 0.02% or less (including 0%) S, 0.04% or less (including 0%) phosphor (P), and the balance Fe and unavoidable impurities, and has a microstructure comprising, in area, 10% or less (including 0%) carbide and the balance austenite.
1 . A steel material having excellent wear resistance, comprising:
in weight percent, 0.55 to 1.4% of carbon (C), 12 to 23% of manganese (Mn), 5% or less (excluding 0%) of chromium (Cr), 5% or less (excluding 0%) of copper (Cu), 0.5% or less (excluding 0%) of Al, 1.0% or less (excluding 0%) of Si, 0.02% or less (including 0%) of S, 0.04% or less (including 0%) of phosphorus (P), and a balance of Fe and unavoidable impurities,
wherein the steel material includes, in area %, 10% or less (including 0%) of carbide and balance austenite, as a microstructure.
2 . The steel material having excellent wear resistance of claim 1 , wherein the steel material has a component segregation index of 3.0 or less, represented by relational expression 1,
Component segregation index ( S )=( C component in central portion of rolled material/ C component in molten steel)/1.25+( Mn component in central portion of rolled material/ Mn component in molten steel)/1.15+( P component in central portion of rolled material/ P component in molten steel)/3.0, [Relational Expression 1]
where a component in the central portion indicates a component in a range of 50 μm or less in upper and lower portions of a part in which a highest component is measured in microstructure analysis at a position equal to half of a thickness of the rolled material.
3 . The steel material having excellent wear resistance of claim 1 , wherein the steel material has a yield strength of 350 MPa or more, a uniform elongation of 20% or more, and an impact toughness of 40 J or more.
4 . A method of manufacturing a steel material having excellent wear resistance, comprising:
preparing a molten steel containing, in weight percent, 0.55 to 1.4% of carbon (C), 12 to 23% of manganese (Mn), 5% or less (excluding 0%) of chromium (Cr) , 5% or less (excluding 0%) of copper (Cu), 0.5% or less (excluding 0%) of Al, 1.0% or less (excluding 0%) of Si, 0.02% or less (including 0%) of S, 0.04% or less (including 0%) of phosphorus (P), and a balance of Fe and unavoidable impurities;
continuous casting operating of obtaining a slab by continuously casting the molten steel under conditions of a molten steel temperature (T C ) satisfying the following relational expression 2 and a casting speed (V) satisfying the following relational expression 3,
K≤T C ≤K+ 60 [Relational Expression 2]
where in relational expression 2, a K value represents a value determined by the following relational expression 4,
V (m/min)≥0.025[ T C −K] [Relational Expression 3]
where in relational expression 3, a K value represents a value determined by the following relational expression 4,
K (° C.)=1536−(69[ C]+ 4.2[ Mn]+ 39[ P] ) [Relational Expression 4]
where [C], [Mn] and [P] each indicate a content (weight %) of an element;
reheating the slab at a reheating temperature (T R ) or lower obtained by the following relational expression 5,
T R =1453−165[ C]− 4.5[ Mn]− 414[ P] [Relational Expression 5]
where T R indicates a reheating temperature (° C.), and [C] and [Mn] each indicate a content (weight %) of an element;
hot rolling the slab reheated in the reheating to a finish rolling temperature of 850 to 1050° C. to obtain a hot rolled steel; and
cooling the hot rolled steel to 600° C. or less at 5° C./sec or more.