Wear 271 (2011) 1854–1861 Contents lists available at ScienceDirect Wear j o ur nal ho me p age: www.elsevier.com/locate/wear Scuffing behavior of gray iron and 1080 steel in reciprocating and rotational sliding J.M. Han a,∗ , R. Zhang a , O.O. Ajayi b , G.C. Barber a , Q. Zou a , L. Guessous a , D. Schall a , S. Alnabulsi c a Oakland University, Automotive Tribology Center, Rochester, MI 48309, USA b Argonne National Laboratory, Energy Technology Division, 9700 S. Cass Ave., Argonne, IL 60439, USA c Physical Electronics, 18725 Lake Drive East, Chanhassen, MN 55317, USA a r t i c l e i n f o Article history: Received 31 August 2010 Received in revised form 26 November 2010 Accepted 27 November 2010 Keywords: Scuffing test Scuffing mechanism Plastic deformation Graphite a b s t r a c t Scuffing damage is catastrophic and typically not self-healing. It severely affects the life and reliability of engineering components, such as cams, roller bearings, piston rings, cylinder bores and gears. Gray iron and 1080 steel are important materials for these extremely demanding structural components. There have been several scuffing studies done in the past with various types of steel and cast iron. However, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. In the present study, scuffing tests were performed with the matrices of gray iron and 1080 steel being fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing behavior for these materials was compared by two types of tests with different motion, i.e. reciprocation and rotation. The experiments were conducted using a high-frequency reciprocating rig and a ball-on-disc rotational rig at variable speeds. The load and the number of cycles for scuffing failure were measured. The results show that the scuffing initiation is due to crack propagation for gray iron and plastic deformation for 1080 steel. It is observed that 1080 steel exhibits higher scuffing resistance than gray iron in reciprocating sliding, whereas it is completely opposite in rotational sliding. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Scuffing is a major problem that limits the life and reliability of mechanical components, such as cams, roller bearings, piston rings, cylinder bores and gears. Typical materials used in these compo- nents are steel and gray cast iron. Scuffing is often recognized by a sudden increase in noise and vibration, sharp increase in sur- face and subsurface temperature and abrupt rise in coefficient of friction. There have been several scuffing studies done in the past with various types of steel and cast iron. Scuffing tests with 52100 steel specimens were conducted by Durkee et al. [1], Shen et al. [2], and Lee et al. [3] to understand scuffing mechanisms. Kim et al. [4] studied the scuffing behavior of 4340 and 1020 steel. Wang et al. [5] employed the technology of low temperature ion sulfu- ration to treat high speed steel, die steel and 1045 steel for scuffing tests. Yoon’s [6] tests were done to study the scuffing transition characteristics of SAE 50B38 steel. Hershberger and Ajayi [7,8] pro- posed a scuffing mechanism for 4340 steel. The scuffing behavior for cast iron was also studied by Clayton [9] and Wang [10]. How- ever, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. ∗ Corresponding author. Tel.: +1 248 838 8030; fax: +1 248 370 2271. E-mail address: jhan@oakland.edu (J.M. Han). The objective of the current research is to conduct and analyze a series of experiments to compare the scuffing behavior of gray cast iron and 1080 steel. The gray cast iron material consists of graphite flakes embedded in a pearlitic matrix, and the 1080 steel studied is fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing character- istics for these materials were compared with two types of tests with different motion, i.e. reciprocation and rotation. In particular Fig. 1. Schematic of ball-on-flat scuffing tester: (a) reciprocating motion; (b) rota- tional motion. 0043-1648/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.wear.2010.11.061