Non-destructive Control in Quality Monitoring of Steel Construction
This work based on literary data discusses the influence of the process of metal fatigue on the change of coercivity. Experimentation on alternate stress (alternating voltage) has resulted in an increase of defects concentration of a structure: pin-hole defects – vacancies, line defects – relocations, volumetric defects – micro separation. The area of reversible damaging was chosen as a criterion of an uninterrupted operation. According to a linear accumulative damage theory (Ψi) there was chosen an amount equal to ratio a number of strain cycles (ni) to the totality of strain cycles at the given strain or load amplitude (Np). It is proposed to consider that in the area of reversible damaging a condition Ψ= (0,2-0,3)δp must be met where δp is a homogeneous deformation of a given steel grade. Devices for testing coercive strength and state standards allowing to define mechanical properties of steel to coercivity.