Patent ID: 6942739
Filing Date: 2005-09-13
Classification: C21D,C23C

Abstract:
1. A process for producing pearlite from an iron containing article having less than 0.77 wt % carbon consisting of the steps of, (a) heating an iron containing article comprising at least 50wt % iron and in which the amount of carbon contained in the article is less than 0.77 wt % down to 0.0 wt % carbon in a non-carburizing atmosphere for a time and at a temperature sufficient to convert at least a portion of said article from a ferritic structure to an austenitic structure, (b) thereafter exposing said austenitic structure, for a time sufficient and at a temperture of about 727 to about 900° C., to a carbon supersaturated CO/H 2 environment consisting essentially of CO and 10 to 50 vol. % H 2 , and having a carbon activity greater than about 1, to disffuse carbon into said austenitic structure and (c) cooling said iron containing article to form a continuous pearlite structure.