The present invention provides a metal wire rod composed of iridium or an iridium alloy, wherein the number of crystal grains on any cross-section in a longitudinal direction is 2 to 20 per 0.25 mm.sup.2, and the Vickers hardness at any part is 200 Hv or more and less than 400 Hv. The iridium wire rod is a material which is produced by a -PD method, and has low residual stress and which has a small change in the number of crystal grains and hardness even when heated to a temperature equal to or higher than a recrystallization temperature (1200 C. to 1500 C.). The metal wire rod of the present invention is excellent in oxidative consumption resistance under a high-temperature atmosphere, and mechanical properties.

The invention includes a copper-nickel-zinc alloy with the following composition in weight %: Cu 47.0 to 49.0%, Ni 8.0 to 10.0%, Mn 0.2 to 0.6%, Si 0.05 to 0.4%, Pb 1.0 to 1.5%, Fe and/or Co up to 0.8%, the rest being Zn and unavoidable impurities, wherein the total of the Fe content and double the Co content is at least 0.1 weight % and wherein mixing silicides containing nickel, iron and manganese and/or containing nickel, cobalt and manganese are stored as spherical or ellipsoidal particles in a structure consisting of an - and -phase. The invention further relates to a method for producing semi-finished products from a copper-nickel-zinc alloy.

Disclosed is a pipe made of an iron-base material, having a corrosion prevention layer formed on the surface thereof. The corrosion prevention layer includes a ZnSn sprayed coating including Sn in a content of more than 1% by mass and less than 50% by mass and the balance composed of Zn. Alternatively, the corrosion prevention layer includes a ZnSnMg sprayed coating including Sn in a content of more than 1% by mass and less than 50% by mass, Mg in a content of more than 0.01% by mass and less than 5% by mass and the balance composed of Zn. Preferably, the sprayed coating of the corrosion prevention layer includes at least any one of Ti, Co, Ni and P, and the content of each of these elements is more than 0.001% by mass and less than 3% by mass.

A high carbon steel wire coil and a production method includes: smelting to obtain molten steel; continuously casting the molten steel to obtain a continuous casting bloom, and performing a reduction with reduction rate that is first high, then low, and then high applied to the continuous casting bloom during continuous casting; heating the continuous casting bloom and then performing blooming to obtain a billet; heating the billet and then performing rolling and air cooling to obtain the wire coil. By finely controlling the dynamic soft reduction parameters during continuous casting, and a reduction with reduction rate that is first high, then low, and then high applied to the continuous casting bloom, the present invention significantly improves the segregation and porosity issues in the central region of the bloom from the source.