A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.

[Object] Provided is a method for manufacturing atomized metal powder having a high amorphous material fraction by using a water atomizing method.

[Solution] A method for manufacturing atomized metal powder in which atomized metal powder having an amorphous material fraction of 90% or more is obtained, the method including ejecting high-pressure water so as to collide with a molten metal stream flowing vertically downward, separating the molten metal stream into metal powder, and cooling the metal powder, in which the high-pressure water collides with the molten metal with a collision pressure of 20 MPa or higher, and in which a temperature of the molten metal and/or a temperature of the high-pressure water are controlled so that the high-pressure water is in a subcritical state or a supercritical state on a collision surface with the molten metal.

A system and method for recovering a high yield of low carbon ferrochrome from chromite and low carbon ferrochrome produced therefrom. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

A method and system for recovering a high yield of low carbon ferrochrome from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

A method for producing a water-atomized prealloyed powder with high cold press formability, includes the following steps: (a) preparing a 400 mesh semi-finished prealloyed powder; (b) controlling the semi-finished prealloyed powder to have a moisture content of 1 wt % to 2 wt % and an oxygen content of 0.6 wt % to 0.8 wt %, and then drying in a vacuum drying oven at 100 C. for 90 minutes to 120 minutes, so that a preliminary bond is produced between powder particles; and (c) reducing, annealing, crushing, and sieving an initially bonded powder particle. The powder is changed from a spheroidal shape to more complex shapes such as rice ear shape, grape shape, and satellite powder, which greatly improves the cold press formability of the prealloyed powder; the method only performs simple surface modification of the powder without changing other properties, and has wide applicability.

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700 C. (preferably 350 to 650 C. and more preferably 450 to 600 C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 m and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.

A method for producing a water-atomized metal powder, comprising applying water to a molten metal stream, dividing the molten metal stream into a metal powder, and cooling the metal powder, wherein the metal powder is further subjected to secondary cooling with cooling capacity having a minimum heat flux point (MHF point) higher than the surface temperature of the metal powder in addition to the cooling and the secondary cooling is performed from a temperature range where the temperature of the metal powder after the cooling is not lower than the cooling start temperature necessary for amorphization nor higher than the minimum heat flux point (MHF point).

Disclosed herein are duplex stainless steel alloys comprising 40 wt %-60 wt % ferrite and 60 wt %-40 wt % austenite and methods of formation thereof, the alloys including or consisting essentially of from 10 wt % to 20 wt % chromium (Cr); from 6 wt % to 13 wt % molybdenum (Mo); from 0.5 wt % to 6.5 wt % nickel (Ni); from 2.25 wt % to 12 wt % manganese (Mn); from 0.05 wt % to 5 wt % copper (Cu); from 0.05 wt % to 0.4 wt % nitrogen (N); from 0.05 wt % to 0.35 wt % carbon (C); from 0.01 wt % to 3.5 wt % cobalt (Co); less than 2 wt % silicon (Si); less than 2 wt % tungsten (W); and iron (Fe) balance.
The duplex stainless steel alloy may include cast or wrought steel, or it may be in powder form.

Aspects of the disclosure are directed to methods and/or apparatuses involving the formation of pore-free or nearly pore-free liquid droplets. As may be implemented in accordance with one or more embodiments, liquid droplets including metal are formed having pores within the liquid droplets. This may involve, for example, atomizing liquid metal with a gas and forming the droplets having pores. The pores are then driven out of the liquid droplets by heating the liquid droplets from a first state in which an outer surface of the droplets has a lower temperature than an inner region thereof, to a second state in which the outer surface has a higher temperature than the inner region.