Stainless steel ribbon for use as a catalyst carrier for automobile exhaust gas and catalyst carrier containing the ribbon coiled into a honeycomb
AssigneeNippon Steel Corporation
InventorsMikio Yamanaka, Keiichi Omura, Masayuki Tendo, Susumu Takemura, Takashi Sato, Tsutomu Ozawa
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Abstract
An Al-containing stainless steel is rapidly solidified from a molten state to produce a ribbon. In catalyst carrier for the exhaust gas of automobile, the Al is utilized for the formation of .alpha.-Al.sub.2 O.sub.3 whiskers, which carry and rigidly bond the .gamma.-Al.sub.2 O.sub.3 powder to the ribbon, as the direct carriers of noble metals.
Claims10
A ribbon for use as a metal honeycomb of a catalyst carrier of a catalyst converter, consisting of an Al-containing stainless steel ribbon having an Al content of 20% or less and an Si coontent of 3% or less, which is produced directly by a process of solidifying the Al-containing stainless steel from a molten state thereof directly into a form of a ribbon at a cooling speed of at least 10.sup.3 .degree.C./sec, thereby forming an Al-concentrated layer on a surface of said ribbon as solidified, said ribbon having as a metallurgical structure a columnar structure with grain boundaries principally oriented in a direction along a thickness of the ribbon and a maximum grain diameter measured perpendicularly to the columnar axis of 30 .mu.m.
A carrier for a catalyst for purification of exhaust gas of an automobile, which is produced by a process of solidifying a ribbon of an Al-containing stainless steel having an Al content of 20% or less and an Si content of 3% or less from a molten state thereof directly into a form of a ribbon at a cooling speed of at least 10 .sup.3 .degree.C./sec, thereby forming an Al-concentrated layer on a surface of said ribbon as solidified, said carrier having as a metallurgical structure a columnar structure with grain boundaries principally oriented in a direction along a thickness of the carrier and a maximum grain diameter measured perpendicularly to the columnar axis of 30 .mu.m, coiling the ribbon at a temperature of at least 500.degree. C. after solidification, and subsequently forming the coiled ribbon into a honeycomb.
Dependencies are inferred from the claim text.