Static and Cyclic Deformation Behavior of the Ferritic Steel 16Mo3 Under Monotonic and Cyclic Loading at High Temperatures

Abstract

The ferritic steel 16Mo3 is commonly used for heat exchangers and steam generators. The temperature loading conditions for these applications range typically from 200 to 500°C. For a basic characterization of the steel 16Mo3, the properties were determined by means of tensile tests with different strain rates. At 200 and 300°C, a negative strain‐rate sensitivity was observed which is due to dynamic strain ageing (Portevin–LeChâtelier effect). To characterize the low cycle fatigue (LCF) behavior of this steel, isothermal strain‐controlled LCF tests were carried out at 200 and 500°C at different strain amplitudes. The cyclic stress response curves are showing principally different courses at the investigated temperatures. The stress relaxation behavior was obtained by cyclic load enhancement tests at various strain amplitudes with dwell times of 30 and 120 s.

Characterization of Low Cycle Fatigue Performance of New Ferritic P92 Steel at High Temperature: Effect of Strain Amplitude

“…Materials under cyclic loadings are divided into two classes: cyclic softening and hardening materials. Several studies showed that ferritic steels are sensitive to softening during LCF and creep‐fatigue loadings at high temperature. The softening behavior of 9%–12%Cr steels is due to the complex microstructure evolutions: transformation of lath structure to dislocation cell/subgrain structure, increasing of subgrain size, coarsening of precipitates, decreasing in average free dislocation density and dislocation recovery process occurring during strain cycling.…”

Fatigue behaviour of 16Mo3 steel at elevated temperatures under uniaxial as well as biaxial‐planar loading

“…The yield strength of the steel 16Mo3 decreases with increasing temperature. The ultimate tensile strength showed a maximum value at 300 °C and decreases with further increasing temperature . The maximum elongation at fracture occurred at 400 °C (A f = 22%).…”

“…The ultimate tensile strength showed a maximum value at 300°C and decreases with further increasing temperature. 32 The maximum elongation at fracture occurred at 400°C (A f = 22%). At the other temperatures, the strain to failure was in the range of 15-18%.…”

Application of a Modified Stress−Strain Approach for the Fatigue‐Life Prediction of a Ferritic, an Austenitic and a Ferritic–Austenitic Duplex Steel under Isothermal and Thermo‐Mechanical Fatigue

“…In order to ensure a constant cooling rate down to temperatures of 100 °C during thermo‐mechanical loading, three in‐line air nozzles were placed at an angle of 120° around the specimens. A more detailed description of both servo‐hydraulic systems is given in previous works of the authors' group …”