Ingenieurwissenschaften und zugeordnete Tätigkeiten
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- Creep-fatigue (1)
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- Tempered martensite-ferritic steel (1)
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- 5 Werkstofftechnik (2) (entfernen)
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The dataset contains experimental mechanical data from complex service-like creep-fatigue experiments performed isothermally at 620 °C and a low strain amplitude of 0.2 % on tempered martensite-ferritic grade P92 steel. The data sets in text file format provide cyclic deformation (min. and max. stresses) and the total (hysteresis) data of all recorded fatigue cycles for three different creep-fatigue experiments: 1) a standard relaxation fatigue (RF) test with symmetrical dwell times of three minutes introduced at minimum and maximum strain, 2) a fully strain-controlled service-like relaxation (SLR) test combining these three-minute peak strain dwells with a 30-minute dwell in between at zero strain, and 3) a partly stress-controlled service-like creep (SLC) test combining the three-minute peak strain dwells with 30-minute dwells at constant stress.
Further information on data and data acquisition, analysis, and experimental details are given in “Experimental Data from Service-Like Creep-Fatigue Experiments on Grade P92 Steel”, submitted to Data in Brief. Additional analyses of these datasets, as well as experimental findings and discussions are presented in “Creep-Fatigue of P92 in Service-Like Tests with Combined Stress- and Strain-Controlled Dwell Times”, submitted to International Journal of Fatigue.
Tempered martensite-ferritic steels, such as the grade P92 steel studied in this contribution, exhibit pronounced macroscopic cyclic softening under isothermal low-cycle fatigue (LCF) and non-isothermal thermomechanical fatigue (TMF) conditions, which is considered to be the predominant degradation mechanism in high-temperature fatigue in this and other material groups. However, such softening processes are highly complex since microscopic (e.g., recovery) and macroscopic (e.g., crack initiation and growth), as well as global and local effects superimpose, especially under creep-fatigue conditions. In this contribution, we discuss the cyclic deformation and softening behavior of P92 in strain-controlled LCF, in-phase (IP) TMF, and out-of-phase (OP) TMF tests with and without dwell times in the temperature range from 300 °C to 620°C. EBSD-based dislocation analysis on various fatigued material states confirms the continuous redistribution and annihilation of geometrically necessary dislocations in all studied states, which can be quantitatively correlated with macroscopic softening despite different damage mechanisms for different test types. Deviations from this correlation are observed for OP TMF and LCF with dwell times, i.e., for conditions where optical microscopy reveals pronounced crack-oxidation interactions at the specimen surfaces.