Article ID Journal Published Year Pages File Type
1628602 Journal of Iron and Steel Research, International 2014 7 Pages PDF
Abstract

The combined effects of different overload ratios (OLRs) and nitriding process on fatigue crack growth (FCG) were analyzed. Steel compact tension specimens made of AISI 4140 steel were subjected to the plasma nitrification process using a gas mixture of 50% N2 and 50% H2 at 500 °C for 2 h. Structural properties of the samples were studied by scanning electron microscopy, optical microscopy, microhardness testing and digital imaging. Plasma nitriding slowed down FCG, but the crack growth retardation caused by the overload was reduced when the OLR was 2. 0 and 2. 5. Nitriding did not take effect when the OLR was 1.5 and 3.0.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys