Characterization of the Fatigue Behaviour of Low Carbon Steels by Means of Temperature and Micromagnetic Measurements

Investigations on low carbon (non- and low-alloy) steels were conducted in form of load increase tests (LIT) and constant amplitude tests (CAT) to find the correlation among material behaviour, mechanical load, and the type of NDT method. With the help of preprogrammed load-free sequences, the thermal impact on magnetic Barkhausen noise (MBN) measurement can be avoided, so that the cyclic deformation properties of material responses can be interpreted more precisely. The results indicate differences between the change in temperature and the MBN-derived variable during LITs and CATs regarding the demonstration of the incubation stage and the cyclic hardening behaviour

Short-Time Fatigue Life Estimation for Heat Treated Low Carbon Steels by Applying Electrical Resistance and Magnetic Barkhausen Noise

Tensile tests and fatigue tests on differently heat-treated low carbon (non- and low-alloy) steels were conducted and accompanied by non-destructive electrical resistometric (ER) and magnetic Barkhausen noise (MBN) measuring devices, in order to establish an improved short-time fatigue life estimation method according to StressLife. MaRePLife (Material Response Partitioning) is the hereby proposed method for calculating S–N curves in the HCF regime, based on the partitioning of material responses acquired during the above-mentioned mechanical tests. The rules were set to make use of the information gathered from pre-conducted tensile tests, which helps to determine the parameters of two load increase tests (LIT) and two constant amplitude tests (CAT). The results of the calculated S–N curves were satisfactory and could be verified by more separately conducted fatigue tests on specimens under different material conditions