Abstract: An improved process for chromizing and chrome-siliconizing 400-series stainless steel components, and in particular, 430 stainless steel components, such as boiler panel studs. The process includes the addition of between 0.12%-0.25% by weight of calcium fluoride salt to the conventional 4% by weight of ammonium chloride activator salt to the coating composition used in known diffusion coating processes. In a more preferred embodiment, small amounts of silicon powder, such as between about 0.12%-0.25% by weight, are added to the two salts and the diffusion coating material. A coating composition is provided as well.

Abstract: A method and apparatus for building a workpiece of a desired geometry by deposit welding with a reusable preform. The reusable preform forms, supports, and cools the deposited molten weld material puddle while the weld material is solidifying thereby eliminating the need for a conventional preform. The reusable preform may be mobile or stationary in any shape, e.g., a block, a cylinder, or a belt. It is manufactured from either a combination of or exclusively of, a ceramic material or a material with high thermal conductivity.

Abstract: This invention relates to a group of modular heat exchangers of the type having a steam chamber, a feedwater chamber, and a feedwater tube passing through the steam chamber to establish fluid communication with the feed chamber.