摘要:
Protection of cast austenitic stainless steel tubes is provided against initiation of carburization by (a) cold-working the inner surfaces of said tubes to deform the surface to such a degree that upon the subsequent heat treatment of step (b) below, dissolution of the M.sub.23 C.sub.6 carbides in the deformed region is accompanied by recrystallization resulting in a refined micrograin structure in the deformed regions to a substantially uniform minimum depth of about 20 microns; and (b) heating the cold-worked inner surfaces of said tubes, for an effective amount of time, at a temperature between its recrystallization temperature and its melting temperature, in an atmosphere of which the oxygen partial pressure is at least oxidizing with respect to chromium.
摘要:
Protection of cast austenitic stainless steel tubes is provided against initiation of carburization by (a) cold-working the inner surfaces of said tubes to deform the surface to such a degree that upon the subsequent heat treatment of step (b) below, dissolution of the M.sub.23 C.sub.6 carbides in the deformed region is accompanied by recrystallization resulting in a refined micrograin structure in the deformed regions to a substantially uniform minimum depth of about 20 microns; and (b) heating the cold-worked inner surfaces of said tubes, for an effective amount of time, at a temperature between its recrystallization temperature and its melting temperature, in an atmosphere of which the oxygen partial pressure is at least oxidizing with respect to chromium.
摘要:
A method of coating metal substrates with a protective aluminum-silicon coating comprising a mixture of (1) an Al-Si eutectic, Al-Si hypereutectic or elemental aluminum and (2) elemental silicon, the articles of manufacture provided by said coating and the method of carrying out thermal hydrocarbon processing operations where corrosion/erosion and other high temperature interactions are a problem using apparatus containing said coatings.
摘要:
Adherent, thermal shock-resistant protective coatings for nickel base super alloys are obtained by applying to the base metal a thin bond coat of an alloy of chromium aluminum and yttrium with materials selected from the group consisting of iron, cobalt, nickel and nickel-cobalt and applying thereover a continuously graded mixture of this material with a zirconia-based ceramic, the concentration of zirconia-based ceramic increasing from the bond coat to the outer layer. The zirconia ceramic may be stabilized by the addition thereto of amounts of magnesium oxide or other materials.
摘要:
A high temperature oxidation resistant alloy of MCrAlY, where M is a base metal comprising iron, cobalt, nickel or a combination thereof, is formed by laser cladding of a coating layer to a substrate.
摘要:
A porous preform is densified by heating while emersed in a precursor liquid. Heating is achieved by passing a current through the preform or by an induction coil immersed in the liquid. Ways to control the densification process are also described.
摘要:
A process for diffusing silicon into iron or iron alloy by heating the iron or iron alloy with silica and a suitable reducing agent in the presence of a catalyst.
摘要:
A process for the co-diffusion of aluminum and other elements into austenitic steel which includes heating the steel to a temperature at which co-diffusion occurs in the presence of a source of aluminum, a catalyst and metallic or metalloid elements having substantial solubility in ferrite (bcc phase of iron or iron alloy) so that a microstructure is formed on the steel which is a single layer composite and which includes a fine dispersion of compatible aluminide particles in a continuous ductile ferrite matrix.
摘要:
Apparatus for heating a fiber using microwave energy. The apparatus has a source of microwave energy feeding and applicator. The applicator is configured to concentrate the microwave energy on a chamber holding a fiber. Fibers made or coated using chemical vapor deposition in the apparatus are also disclosed.
摘要:
Apparatus for heating a fiber using microwave energy. The apparatus has a source of microwave energy feeding and applicator. The applicator is configured to concentrate the microwave energy on a chamber holding a fiber. Fibers made or coated using chemical vapor deposition in the apparatus are also disclosed.