TY - JOUR
T1 - Effect of Surface Hardening Technique and Case Depth on Rolling Contact Fatigue Behavior of Alloy Steels
AU - Xie, Lechun
AU - Palmer, David
AU - Otto, Frederick
AU - Wang, Zhanjiang
AU - Jane Wang, Q.
N1 - Funding Information:
This work was supported by BRP US, Inc., and the Center for Surface Engineering and Tribology at Northwestern University, with technical assistance from Midwest Thermal Vac. Lechun Xie acknowledges the scholarships from the China Scholarship Council (No. 2011623074) and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, China.
Publisher Copyright:
© 2015, Copyright © Society of Tribologists and Lubrication Engineers.
PY - 2015/3/4
Y1 - 2015/3/4
N2 - Surface hardening techniques are widely used to improve the rolling contact fatigue (RCF) resistance of materials. This study investigated the RCF resistance of hardened, ground steel rods made from three different aircraft-quality alloy steels (AISI 8620, 9310, and 4140) and hardened using different techniques (atmosphere carburizing, vacuum carburizing, and induction hardening) at different case depths. The RCF life of the rods was determined using a three ball-on-rod rolling contact fatigue test machine. After testing, the microstructures of the rods were examined using metallographic techniques. The stress distributions and plastic deformation zones for the specimens under RCF were calculated using an elastoplastic model for plastically graded materials. Relationships between surface hardness, case depth, and RCF life were investigated. The longest lives were observed for the vacuum-carburized AISI 9310 specimens, and the shortest lives were observed for the induction-hardened AISI 4140 specimens. It is concluded that the most important factors in determining the RCF lives of high-cleanliness surface-hardened alloy steels are (1) the hardness in the region of highest octahedral shear stress (in this case, ∼0.13 mm beneath the surface) and (2) the depth of high hardness (>613 HV), which determines the plastic deformation zone size.
AB - Surface hardening techniques are widely used to improve the rolling contact fatigue (RCF) resistance of materials. This study investigated the RCF resistance of hardened, ground steel rods made from three different aircraft-quality alloy steels (AISI 8620, 9310, and 4140) and hardened using different techniques (atmosphere carburizing, vacuum carburizing, and induction hardening) at different case depths. The RCF life of the rods was determined using a three ball-on-rod rolling contact fatigue test machine. After testing, the microstructures of the rods were examined using metallographic techniques. The stress distributions and plastic deformation zones for the specimens under RCF were calculated using an elastoplastic model for plastically graded materials. Relationships between surface hardness, case depth, and RCF life were investigated. The longest lives were observed for the vacuum-carburized AISI 9310 specimens, and the shortest lives were observed for the induction-hardened AISI 4140 specimens. It is concluded that the most important factors in determining the RCF lives of high-cleanliness surface-hardened alloy steels are (1) the hardness in the region of highest octahedral shear stress (in this case, ∼0.13 mm beneath the surface) and (2) the depth of high hardness (>613 HV), which determines the plastic deformation zone size.
KW - Carburizing
KW - Case Depth
KW - Ferrous Alloys, Steel
KW - Hardening
KW - Hardness
KW - Metallurgical Analysis
KW - Optical Microscopy
KW - Rolling Contact Fatigue
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U2 - 10.1080/10402004.2014.960957
DO - 10.1080/10402004.2014.960957
M3 - Article
AN - SCOPUS:84921518973
SN - 1040-2004
VL - 58
SP - 215
EP - 224
JO - Tribology Transactions
JF - Tribology Transactions
IS - 2
ER -