Surface Modification by Friction Stir Processing of Low-Carbon Steel: Microstructure Investigation and Wear Performance

Journal Article · Wed Feb 14 23:00:00 EST 2018 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-017-3087-7· OSTI ID:22860673

Sattari, Behnoosh; Shamanian, Morteza ^[1]; Salimijazi, Farshid ^[2]; Salehi, Mehdi ^[1]

---

1. Isfahan University of Technology, Department of Materials Engineering (Iran, Islamic Republic of)
2. Tennessee Technological University, Department of Mechanical Engineering (United States)

A low-carbon steel sheet with a thickness of 5 mm was subjected to friction stir processing (FSP) by one to four different passes. The microstructures of different regions were characterized using the optical microscopy and electron backscatter diffraction. The Vickers micro-harness was measured at the distance of 200 μm below the processed surfaces. The influence of pass numbers (PNs) on wear resistance was studied in terms of coefficients of friction (CoFs), weight losses and wear rates. SEM topographies of the worn surfaces were also studied to evaluate the wear mechanisms. Microstructure observations showed that Widmänstatten ferrite plates were formed in stir zones (SZs) and heat affected zones. As PN increased, these grains were widened due to the increment of the carbon diffusivity and lengthened because of the high heat input and microstructure anisotropy. Besides, increasing the PN causes increasing of the hardness and wear resistance, simultaneously. Specifically, the wear rate in the SZ was reduced from 2.8 × 10{sup −2} mm{sup 3} m{sup −1} in base metal to 0.3 × 10{sup −2} mm{sup 3} m{sup −1} in sample which was subjected to 4 FSP passes. However, variation in PN had no considerable effect on CoFs. Oxidative wear mechanism was observed on the worn surface of the steel and the FSPed samples while more debris was formed by increasing the PNs.

• OSTI ID: 22860673
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 2 Vol. 27; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADHESIVES
ANISOTROPY
BACKSCATTERING
ELECTRON DIFFRACTION
FERRITE
FRICTION
HARDNESS
HEAT AFFECTED ZONE
LOW CARBON-HIGH ALLOY STEELS
MICROSTRUCTURE
OXIDATION
SCANNING ELECTRON MICROSCOPY
SURFACES
THICKNESS
WEAR RESISTANCE