SBIR Phase I: An Innovative Process to Produce Powder for Fabrication of Ferritic Stainless Steel

* 9761114莫耶 这个小企业创新研究第一阶段项目旨在生产高压缩性低氧化物铁粉，该铁粉涂有浓度足以在铬通过高温烧结扩散到铁中后产生铁素体不锈钢的铬。 通过注入足够浓度的含铬溶液使铬沉积在高纯水雾化的铁粉上，从而在流化床中使铬涂层沉积在铁粉上。 目前，提议者用压缩性有限的预合金不锈钢粉末制造不锈钢零件。 由于颗粒表面高度氧化，它们难以还原，限制了烧结性和耐腐蚀性。 10微米铬粉末与水雾化粉末的元素混合物减轻了低压缩性和差的耐腐蚀性，但是低氧的10微米铬粉末难以商业生产。 如果生产涂覆的铬粉末，则可以生产更致密的部件。 更致密的零件提高了耐腐蚀性、磁感应强度和抗拉强度。 增加的纯化改善了延展性和结构敏感的磁性。 如果是这样，则可以生产具有改进的耐腐蚀性的磁性部件。提议者的部件，除非是锻造的，否则含有孔隙。 多孔部件易受腐蚀。增加孔隙度会降低密度。 涂层铁粉允许生产更纯净和密度更高的零件。 因此，应提高耐腐蚀性、磁性和高温性能。 如果这一过程证明是成功的，提议者将考虑建造或扩建一座工厂，以商业数量生产这种粉末。 ***

*** 9761114 Moyer This Small Business Innovation Research Phase I project is designed to produce high compressibility low oxide iron powder that is coated with chromium in concentration sufficient to yield ferritic stainless steel once the chromium is diffused into the iron by high temperature sintering. Chromium will be deposited on high purity water atomized iron powder by injecting chromium-containing solution of sufficient concentration to permit deposition of a chromium coating on iron powder in a fluidized bed. Presently, the proposer fabricates stainless steel parts from prealloyed stainless steel powder that is limited in compressibility. Since particle surfaces are highly oxidized, they are difficult to reduce, limiting sinterability and corrosion resistance. Elemental admixtures of 10 micron chromium powder with water atomized powder alleviate low compressibility and poor corrosion resistance, but a low oxygen 10 micron chromium powder is difficult to produce commercially. If coated chromium powder is produced, denser parts can be produced. Denser parts improve corrosion resistance, magnetic induction and tensile strength. Increased purification improves ductility and structure sensitive magnetic properties. If so, magnetic parts with improved corrosion resistance can be produced. The proposer's parts, unless forged, contain porosity. Porous parts are subject to corrosion. Increasing porosity lowers density. Coated iron powder permits production of parts that are purer and higher in density. Therefore, corrosion, magnetic and high temperature properties should be enhanced. If the process prove successful, the proposer would consider construction or expansion of a plant to produce the powder in commercial quantities. ***