Method of finishing a steel article having a boronized and carburized case
AssigneeHughes Tool Company
InventorStanley R. Scales
Life of this patent
Estimating the term…
Abstract
Disclosed herein is an improved method of finishing a steel article having a carburized and boronized case. The article is carburized to a selected depth then finished to a smoothness which is smoother than the desired final finish. The article is then boronized, hardened and tempered. Further finishing is unnecessary.
Claims7
The method of manufacturing steel friction bearing members requiring a strong and tough wear resistant surface, said method comprising the steps of:
- carburizing said surface to produce a carburized case of selected depth;
- applying a finish to the carburized surface smoother than the desired final smoothness;
- boronizing the carburized case;
- hardening the carburized case;
- and
- tempering the carburized case.
The method of manufacturing steel friction bearing members requiring a strong and tough wear resistant surface, said method comprising the steps of:
- carburizing said surface to a case depth of at least 0.030 inch;
- finishing said carburized surface to 32 microinch RMS or better;
- then
- boronizing the finished carburized surface to a depth of at least 0.001 inch;
- quenching said carburized case from temperature to produce a martensitic grain structure;
- tempering said carburized case to produce a tempered martensitic grain structure;
- whereby the wear resistant boronized surface has a tough and strong supporting base to sustain large loads and avoid brittle fracture and a smooth final finish requiring no further finishing.
The method of manufacturing steel friction bearing members requiring a strong and tough wear resistant surface, said method comprising the steps of:
- carburizing said surface to a case depth of at least 0.030 inch;
- finishing said carburized surface to a finish of 32 microinches RMS or better;
- boronizing the finished carburized surface to a depth of at least 0.001 inch;
- quenching said carburized case from a temperature of at least 1390.degree. F. to produce a martensitic grain structure;
- and
- tempering said carburized case from a temperature within a range of 290.degree. through 510.degree. for about one hour to produce a tempered martensitic grain structure.
Dependencies are inferred from the claim text.