Manufacturing influences on the fatigue properties of quenched and tempered SAE 4140 specimens

✍ Scribed by M. Klein; P. Starke; D. Eifler

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 438 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.197

✦ Synopsis

To analyse interactions between the manufacturing process chains, its design, variations in material properties, especially the microstructure and the resulting component properties, specimens with tension screw geometry were machined with specific varying process chains. According to the specific process chain the surface integrity and consequently the fatigue behaviour of the specimens is influenced in a characteristic manner. The cyclic deformation behaviour of these components can be benchmarked with conventional strain measurements as well as with high-precision temperature and electrical resistance measurements. The development of temperaturevalues provides substantial information. Furthermore, electrical resistance measurements enable the monitoring of proceeding fatigue damage during scheduled maintenances without any mechanical load. The physically based fatigue life calculation method "PHYBAL" was modified to calculate the lifetime.