Bending Fatigue Strength of Austempered Ductile Iron Spur Gears

Abstract

This paper deals with an experimental evaluation of bending fatigue strength for austempered ductile iron (ADI) spur gears. The module is 2.5 and the number of teeth is 26 in the test gears. The material of the test gears corresponds to Japan Industrial Standard (JIS) FCAD1100-15. Some gears are processed by one of two types of fine particle bombarding (FPB). The surface roughness is slightly increased by FPB. The obtained strengths are 623 MPa for the as-austempered gears, and 1011 and 1085 MPa for the gears after FPB. The strength is expressed by the fillet stress level, which is calculated by FEM. The strength of a gear with the same dimensions made of carburized SCr420H alloy steel is 1205 MPa, and the strength of the ADI gear is approximately half that of the carburized steel gear. The FPB process has a significant effect on the ADI gear, improving its strength by 62-74%.

Östemperlenmiş Küresel Grafitli Dökme Demirlerde İndüksiyonla Yüzey Sertleştirmenin Yorulma Sınırı Üzerine Etkisi

“…Elde edilen dökme demirin kimyasal bileşimi Tablo 1'de verilmiştir. ( Östemperleme ile yorulma sınırındaki bu artış, ince ösferritik yapının perlitik yapıya göre yorulma çatlaklarının ilerlemesine karşı direncini artırdığına dayandırılmaktadır [10,[27][28][29][30][31][32][33][34][35][36].…”

“…Mikro çatlak tumuşak ve sünek ferritik yapıda daha kolay ve hızlı yayılmaktadır[26].Yüksek karbonlu östenit + beynitik ferrite sahip ÖKGDD numunesinde KGDD numunesinden daha yüksek yorulma sınırı elde edilmiştir. Bu sonuç literatürle paralellik göstermektedir[2,10,[27][28][29][30][31][32][33][34].…”

Comparison of Bending Fatigue Strength among Spur Gears Manufactured by Various Methods (Influence of Manufacturing Method on Bending Strength)

“…In the ADI gear, the hardness is low around the graphite grains, and we avoid measurements above such areas. The hardness exhibits large variation and is considered to be uniform along the depth because there is no tendency in the distribution, such as a rise from the core to the surface (8) . The hardness is almost the same as the core hardnesses of the forged and hobbed gears.…”

“…ADI has not been applied to power transmission gears because the bending fatigue strength of ADI gears is low compared with that of case-hardened steels. Yamanaka obtained the bending fatigue strength of ADI gears and examined the suitability of ADI as a gear material (8) . The strength of each type of gear has been evaluated, but there is no study on comparing the strengths of these four gears.…”

Influence of Ferrosilicon Manganese on the Sulphur Content and Microstructure in the Production of Austempered Ductile Iron (Adi)

“…In recent years, Austempered Ductile Iron (ADI), obtained from ductile iron, has attracted considerable applications because of its good mechanical properties. Such properties include resistance to fatigue [1][2][3][4], good wear resistance [5,6], high strength with good ductility [7][8][9] and good rolling contact resistance [10]. The density of ADI is lower than steel [8,12] which makes it more applicable in the areas of production of engine blocks and other engineering components.…”