Enhancement of rolling contact fatigue performance of ferrite–pearlite steel with laser shock peening

Abstract

The laser shock peening effect and its influence on rolling contact fatigue of ferrite-pearlite steel were investigated experimentally. Microhardness on the steel surface is increased after laser shock treatment. The depth of surface layer affected by laser shock hardening is above 1 mm. The maximum residual compressive stress generated on the specimen surface is around 1 GPa. The twin-disk test showed that laser shock-treated steel disk presents better rolling contact fatigue resistance than untreated one. Laser shock-induced strain hardening and compressive residual stress alter crack inclination angle and propagation behavior, which results in a longer fatigue life.

Microstructure evolution of railway pearlitic wheel steels under rolling-sliding contact loading

“…In a study [26] of RCF tests for untreated and laser shock peening (LSP) treated ER8 wheel, it was found that the magnitude of strain hardening of untreated wheel steel with lower matrix hardness was larger than LSP-treated steels. The LSP usually does not change the microstructure of the wheel material, so this result means that the magnitude of strain-induced hardening decreased with the increasing matrix hardness for the same wheel material.…”