TY - JOUR

T1 - On the fatigue behavior of ultrafine-grained interstitial-free steel

AU - Niendorf, Thomas

AU - Canadinc, Demircan

AU - Maier, Hans Jürgen

AU - Karaman, Ibrahim

AU - Sutter, Steve G.

PY - 2006/10

Y1 - 2006/10

N2 - The present paper reports on the cyclic stress-strain response of body-centered cubic ultrafine-grained (UFG) interstitial-free (IF) steel severely plastically deformed at room temperature utilizing equal channel angular extrusion (ECAE). Low-cycle fatigue tests were conducted with various strain amplitudes and strain rates on samples obtained through different ECAE routes and number of ECAE passes in order to determine the optimum processing route(s) for improved fatigue response of this material. UFG IF steel is superior to its coarse grained counterpart under both monotonic and cyclic loading in terms of properties, such as stress ranges tolerated, strength levels attained, and the corresponding fatigue behavior. All UFG steels subjected to more than 4 ECAE passes exhibit stable cyclic stressstrain response. Moreover, it was shown that dynamic grain coarsening, which usually leads to cyclic softening in UFG materials, is not prevalent in the ECAE processed UFG IF steel. For representing the fatigue life of UFG IF steel, the parameter after Smith, Watson and Topper, which is an indication of energy dissipation per cycle, proved adequate while comparing materials obtained through different ECAE routes.

AB - The present paper reports on the cyclic stress-strain response of body-centered cubic ultrafine-grained (UFG) interstitial-free (IF) steel severely plastically deformed at room temperature utilizing equal channel angular extrusion (ECAE). Low-cycle fatigue tests were conducted with various strain amplitudes and strain rates on samples obtained through different ECAE routes and number of ECAE passes in order to determine the optimum processing route(s) for improved fatigue response of this material. UFG IF steel is superior to its coarse grained counterpart under both monotonic and cyclic loading in terms of properties, such as stress ranges tolerated, strength levels attained, and the corresponding fatigue behavior. All UFG steels subjected to more than 4 ECAE passes exhibit stable cyclic stressstrain response. Moreover, it was shown that dynamic grain coarsening, which usually leads to cyclic softening in UFG materials, is not prevalent in the ECAE processed UFG IF steel. For representing the fatigue life of UFG IF steel, the parameter after Smith, Watson and Topper, which is an indication of energy dissipation per cycle, proved adequate while comparing materials obtained through different ECAE routes.

KW - Body-centered cubic

KW - Equal channel angular extrusion

KW - Fatigue life

KW - Interstitial free steel

KW - Ultrafine grained microstructure

UR - http://www.scopus.com/inward/record.url?scp=33750493876&partnerID=8YFLogxK

U2 - 10.3139/146.101377

DO - 10.3139/146.101377

M3 - Article

AN - SCOPUS:33750493876

VL - 97

SP - 1328

EP - 1336

JO - International Journal of Materials Research

JF - International Journal of Materials Research

SN - 1862-5282

IS - 10

ER -