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Strengthening Improvement on Gear Steels
Author(s) -
Mengaroni S.,
Bambach M. D.,
Cianetti Filippo,
Bleck W.,
Neri S.
Publication year - 2016
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.201500155
Subject(s) - materials science , toughness , metallurgy , refining (metallurgy) , carburizing , silicon , service life , nucleation , slag (welding) , composite material , chemistry , organic chemistry
18CrNiMo7‐6 carburizing steel grade is commonly used to produce high‐performance gear components, e.g., for wind energy converters. Component failure is often related to cracks taking origin in correspondence of non‐metallic inclusions. In order to increase the component's service life, a high degree of steel cleanliness has been pursued so far. However, cracks may still occur leading to preliminary component failure and high maintenance costs. For this reason, a special matrix is developed with the purpose to reach higher resistance without losing toughness and guaranteeing high steel cleanliness as well. The nominal chemical composition of standard 18CrNiMo7‐6 steel is modified by nickel and silicon additions. The steel is produced by vacuum induction melting (VIM) followed by electro‐slag refining (ESR) in order to further increase its cleanliness. Results of nickel and silicon addition show a growing trend of strength values without any significant loss in toughness behavior at room temperature. The reduction of inclusion content by ESR leads moreover to fewer cracks nucleation sites.