PRODUCTION OF FERROUS SINTERED ALLOY, FERROUS SINTERED ALLOY PRODUCED THEREBY AND BEARING CAP

摘要

PROBLEM TO BE SOLVED: To produce a ferrous sintered alloy in which the machinability of a desired part is improved by coating the desired part on the surface of a powdery compact for a ferrous sintered alloy contg. carbon with a pasty coating material contg. a boron compound and then executing sintering at the diffusing temp. or above of carbon. ;SOLUTION: Powder for a ferrous sintered alloy contg. carbon is compacted to obtain a powdery compact. This powdery compact is, if required, heated to the diffusing temp. of carbon or below, e.g. to about ≤900°C to obtain a pearlite-ungenerated tentative sintered compact. The desired part, e.g. the part to be subjected to machining in the powdery compact or tentative sintered compact is coated with a pasty coating material contg. a boron compound such as boric acid, borax, boron oxide or the like, or a film contg. the boron compound and pyrolytic resin is fixed thereto. Next, these are sintered at the diffusing temp. or above of carbon, e.g. at about 1130°C. In this way, a high hardness ferrous sintered alloy having a ferritic free-cutting layer formed by the infiltration of of the boron compound can be obtd.;COPYRIGHT: (C)1998,JPO