How to Improve the Fatigue Properties of Sintered Steels by Combined Mechanical and Thermal Surface treatment

Author:  Sonsino, Schlieper, Huppmann
Source:  Modern Developments in Powder Metallurgy Vol. 16, June '84
Doc ID:  1984106
Year of Publication:  1984
Abstract:  
The ever increasing demand for sintered components with improved dynamic properties, in which the influence of shot peening, carbonitriding and combinations thereof on the endurance limit of Fe-Cu and Fe--Cu--Ni sintered alloys was determined. Two density levels, 7.1 and 7.4 g/cm exp 3, were investigated. The fatigue tests were carried out on unnotched round test specimens and on large notched specimens. Compared with the as sintered condition, improvements of fatigue limits of the order of 70% could be realized. Sintered steel must be considered as a candidate for designing highly stressed engineering components like passenger car connecting rods or gear box parts. Descriptors: Copper steels-- Mechanical properties; Nickel steels-- Mechanical properties; Powder metallurgy parts-- Mechanical properties; Shot peening; Carbonitriding; Fatigue limit-- Microstructural effects; Connecting rods-- Powder technology