A copper alloy consisting of two or more of Cr, Ti and Zr, and the balance Cu and impurities, in which the relationship between the total number N and the diameter X satisfies the following formula (1). Ag, P, Mg or the like may be included instead of a part of Cu. This copper alloy is obtained by cooling a bloom, a slab, a billet, or a ingot in at least in a temperature range from the bloom, the slab, the billet, or the ingot temperature just after casting to 450° C., at a cooling rate of 0.5° C./s or more. After the cooling, working in a temperature range of 600° C. or lower and further heat treatment of holding for 30 seconds or more in a temperature range of 150 to 750° C. are desirably performed. The working and the heat treatment are desirably performed a plurality of times.

log N≦0.4742+17.629×exp(−0.1133×X)  (1)

The present disclosure provides a welding electrode and methods of manufacturing the same. The welding electrode can include a composite body having a tip portion and an end portion. The composite body can include a shell defining a cavity through the end portion, the shell comprising a first metal that includes one or more of the following: a precipitation hardened copper alloy, copper alloy, and carbon steel. The composite body can also include a core within the shell, the core extending through the shell from the tip portion to the cavity, the core comprising a second metal that includes dispersion strengthened copper. The core and the shell have a metallurgical bond formed from co-extrusion.

There are provided a copper alloy for a bearing and a bearing, which can prevent seizure in Mn-Si primary crystals. The copper alloy for a bearing and the bearing according to the present invention contain 25 wt % or more and 48 wt % or less of Zn, 1 wt % or more and 7 wt % or less of Mn, 0.5 wt % or more and 3 wt % or less of Si, and 1 wt % or more and 10 wt % or less of Bi, the balance consisting of inevitable impurities and Cu, and are characterized in that, in a sliding surface on which a counter material slides, the proportion of triangles having an area of 5000 μm.sup.2 or more and including no Bi particle with a circle equivalent diameter of 10 μm or more, among triangles having the closest three Mn-Si primary crystals as apices, is 20 % or less.

A nozzle put into a molten metal in vertical upwards continuous casting for casting a cast product by pulling up the molten metal, the nozzle includes a nozzle body having an intake hole through which the molten metal is taken in and which is formed in a lateral surface of the nozzle body and a flange portion formed on lower side of the intake hole and projecting beyond the nozzle body.

A method for producing a Cu—Ni—Sn alloy, which achieves both productivity and product quality by reducing internal cracks and dispersing Sn uniformly while shortening the time for cooling an ingot. The method for producing a Cu—Ni—Sn alloy is a continuous casting method or a semi-continuous casting method that includes pouring a molten Cu—Ni—Sn alloy from one end of a mold, both ends of which are open, and continuously drawing out the alloy as an ingot from the other end of the mold while solidifying a part of the alloy, the part being near the mold; performing primary cooling by spraying a liquid mist on the drawn-out ingot; and performing secondary cooling by immersing the ingot having been subjected to the primary cooling in a liquid, thereby making a cast product of the Cu—Ni—Sn alloy.

The electrode for welding sheets of steel or aluminum, with a conductivity greater than or equal to 90% IACS and made of an alloy including, by weight based on the total weight of the alloy, chromium in a proportion higher than or equal to 0.1% and lower than 0.4%, between 0.02 and 0.04% of zirconium, lower than 0.015% of phosphorus, the remainder being copper and less than 0.1% of unavoidable impurities. The electrode structure advantageously includes incoherent chromium precipitates, more than 90% of which have a projected surface area of less than 1 μm.sup.2, the precipitates having a size of between 10 and 50 nm. The electrode has a fiber structure of radial fibers, each fiber having a thickness of less than 1 mm and a substantially central fibreless region that has a diameter of less than 5 mm. The invention also relates to a method for producing the electrode.

The invention relates to a process of producing a non-ferrous metallic tube, in which process comprises a casting stage, in which a cast tube having an outer diameter of 20-70 mm, preferably 35-55 mm and a wall thickness of 1.0-4.0 mm, preferably 2.0-3.0 mm, is casted from melt by continuous upward vertical casting process, and the casting stage is followed by at least two drawing stages. In the drawing stages drawing direction of the cast tube in at least two each other following drawing stages is opposite to each other.--

The present invention provides a method for producing a Cu—Ni—Sn alloy, which achieves both productivity and product quality by reducing internal cracks and dispersing Sn uniformly while shortening the time for cooling an ingot. The method for producing a Cu—Ni—Sn alloy is a method for producing a Cu—Ni—Sn alloy by a continuous casting method or a semi-continuous casting method, the method including: pouring a molten Cu—Ni—Sn alloy from one end of a mold, both ends of which are open, and continuously drawing out the alloy as an ingot from the other end of the mold while solidifying a part of the alloy, the part being near the mold; performing primary cooling by spraying a liquid mist on the drawn-out ingot; and performing secondary cooling by immersing the ingot having been subjected to the primary cooling in a liquid, thereby making a cast product of the Cu—Ni—Sn alloy.

There is provided a method for producing a Cu—Ni—Sn alloy by a continuous casting method or a semi-continuous casting method, the method including pouring a molten Cu—Ni—Sn alloy from one end of a mold, both ends of which are open, and continuously drawing out the alloy as an ingot from the other end of the mold while solidifying a part of the alloy, the part being near the mold; and spraying mist-like liquid on the drawn-out ingot to cool the ingot, thereby making a cast product of the Cu—Ni—Sn alloy.

A high-efficiency and short-process method for preparing a high-strength and high-conductivity copper alloy is disclosed, comprising the following steps: performing horizontal continuous casting to obtain an as-cast primary billet of copper alloy, wherein the alloying elements in the obtained as-cast primary billet being in a supersaturated solid solution state; after peeling the obtained as-cast primary billet, directly performing continuous extrusion, cold working and aging annealing treatment to obtain a copper alloy, and keeping the alloying elements of the billet in a supersaturated solid solution state during the process of continuous extrusion. The method shortens the flow, reduces energy consumption and improves the product forming rate.