An NPR non-magnetic steel material for rock bolt and a production method thereof are disclosed. The NPR non-magnetic steel material for rock bolt has a composition, in weight percent, consisting of: C: 0.4-0.7%, Mn: 15-20%, Cr: 1-18%, Si: 0.3-3%, Ca: 0.05-0.15%, Cu: ≤0.03%, Ni: ≤0.02%, S: ≤0.001%, P: ≤0.001%, and the rest being Fe and unavoidable impurity elements. The NPR non-magnetic steel material for rock bolt and the production method thereof effectively solve the problems of steel materials for rock bolt in the prior art such as strong magnetism, low tensile strength and low effective elongation. The NPR non-magnetic steel material for rock bolt has a fully-austenitized structure and is non-magnetic, its yield strength is adjustable in the range of 600-1000 MPa, and its elongation is adjustable in the range of 20-60%.

A magnesium alloy sheet containing, relative to 100 wt % of the entire magnesium alloy sheet, 2.7 to 5.0 wt % of Al, 0.75 to 1.0 wt % of Zn, 0.1 to 1.0 wt % of Ca, 1.0 wt % or less of Mn (excluding 0 wt %), and the balance of Mg and other inevitable impurities, wherein a volume fraction of bottom crystal grains, relative to 100 vol % of overall crystal grains of the magnesium alloy sheet, is 30% or less, and the bottom crystal grains are crystal grains in a <0001>//C-axis direction.

The present invention relates to a magnesium alloy sheet and a manufacturing method thereof. In detail, the magnesium alloy sheet includes 0.5 to 3.5 wt % of Al, 0.5 to 1.5 wt % of Zn, 0.1 to 1.0 wt % of Ca, 0.01 to 1.0 wt % of Mn, a remainder of Mg, and other inevitable impurities with respect to an entire 100 wt % of a magnesium alloy sheet, wherein an average crystal grain size of the magnesium alloy sheet is 3 to 15 m, the magnesium alloy sheet includes a stringer, and a length of the stringer in a rolling direction (RD) is equal to or less than the maximum value of 50 m.

A method for producing a hot-rolled titanium plate includes, [1] melting at least one part of the side surface of the titanium slab by radiating a beam or plasma toward the side surface, not toward the surface to be rolled, and thereafter causing re-solidification to form, in the side surface, a layer having grain diameter of 1.5 mm or less and a depth of 3.0 mm or more from the side surface; [2] performing a finishing process on the surface to be rolled of the titanium slab in which the layer is formed, to thereby bring a slab flatness index X to 3.0 or less; and [3] subjecting the titanium slab after the finishing process to hot rolling under a condition in which a length of an arc of contact of a roll L in a first pass of rough rolling is 230 mm or more.

A copper alloy material manufacturing equipment for manufacturing a copper alloy material by continuously casting molten copper. The equipment includes an element adding means for adding a metal element to the molten copper, a tundish for holding the molten copper containing the metal element, a pouring nozzle connected to the tundish to feed the molten copper from the tundish, and a trapping member arranged inside the tundish and including a same type of material as at least one of an oxide of the metal element, a nitride of the metal element, a carbide of the metal element and a sulfide of the metal element.

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.

This copper alloy wire is a copper alloy wire which is made of a precipitation hardening-type copper alloy containing Co, P, and Sn and is manufactured using a continuous cast-rolling method or cold working of a continuous cast wire rod manufactured using a continuous casting method, in which the copper alloy wire has a composition including Co: more than or equal to 0.20 mass % and less than or equal to 0.35 mass %, P: more than 0.095 mass % and less than or equal to 0.15 mass %, and Sn: more than or equal to 0.01 mass % and less than or equal to 0.5 mass % with a balance being Cu and inevitable impurities.

Provided is a material for hot stamping including: a steel sheet including carbon (C) in an amount of 0.28 wt % to 0.50 wt %, silicon (Si) in an amount of 0.15 wt % to 0.70 wt %, manganese (Mn) in an amount of 0.5 wt % to 2.0 wt %, phosphorus (P) in an amount less than or equal to 0.05 wt %, sulfur (S) in an amount less than or equal to 0.01 wt %, chromium (Cr) in an amount of 0.1 wt % to 0.5 wt %, boron (B) in an amount of 0.001 wt % to 0.005 wt %, balance iron (Fe), and other inevitable impurities; and fine precipitates distributed in the steel sheet, wherein the fine precipitates include nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V), and trap hydrogen.

An exemplary embodiment of the present invention relates to a magnesium alloy sheet and a manufacturing method thereof. According to an exemplary embodiment of the present invention, a magnesium alloy sheet including 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.002 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to a total of 100 wt % of the magnesium alloy sheet, may be provided.

A high-efficient rolling process for magnesium alloy sheet. The process is a rolling process for rolling billets. Parameters of the rolling process are: the rolling speed of each rolling pass is 1050 m/min, the rolling reduction of each rolling pass is controlled to be 4090%, and both the preheating temperature before rolling and the rolling temperature of each rolling pass are 250450 C. A preparation method for magnesium alloy sheet. The method comprises the steps of: 1) preparing rolling billets; 2) high-efficient hot rolling: controlling the rolling speed of each rolling pass to be 1050 m/min, controlling the rolling reduction of each rolling pass to be 4090%, and controlling both the preheating temperature before rolling and the rolling temperature of the each rolling pass to be 250450 C.; and 3) performing annealing. By means of the rolling process, mechanical performance of the sheet can be also effectively improved, and especially, the strength and ductility of the sheet can be greatly improved.