EVALUATION OF THE FATIGUE STATE OF EQUIPMENT FROM AUSTENITIC STAINLESS STEELS
In stainless austenitic metastable steels at production stage and during the operation life, occur technological and operational phase transformations, resulting in accumulation of ferritic phase. Heating and deformation in production and heating pressure loads and other parameters in operating lead to ferritization, and fatigue type degradation, accumulation of damage at micro level. Most effective monitoring of such two-parameter degradation can be carried out using a non-destructive method to measure the magnetic characteristic, the coercive force.
Applications:
● Nuclear power plants,
● Oil & gas industry,
● Chemical,
● Food industry.
Equipment:
● Magnetic structurescope (coercimeter) MC-04H-2
Steel grade: |
● 12X18H10T (chemical composition: C – 0.98; Mn – 1.33; Si – 0.66; ● 08X18H9 (C – 0.036; Mn – 1.73; Si – 0.42; Cr – 18.2; Ni – 8.2; Ti ≤ 0.1; |
Tension test specimens: | strip-shaped |
Form of samples for cyclic hydraulic internal pressure tests: |
● pipe segments diameters 73 and 42 mm wall thicknesses of 3 and 1 mm ● spherical hollow cylinders diameter 130 mm and wall thickness 3 mm |
Cyclic tests mode: | low-cycle fatigue mode |
Limit of load: | fatigue |
Coercive force variation: | from 0 to 45 A/cm |