TY - JOUR

T1 - Development of Material Sensors Made of Metastable Austenitic Stainless Steel for Load Monitoring

AU - Gansel, René

AU - Heinrich, Christian

AU - Lohrengel, Armin

AU - Maier, Hans Jürgen

AU - Barton, Sebastian

N1 - Publisher Copyright: © The Author(s) 2024.

PY - 2024/9/3

Y1 - 2024/9/3

N2 - Metastable stainless steels can be used as a load-sensitive sensor. In combination with an eddy current testing system, mechanical overloads of a component can be detected directly during operation. Material sensors were prepared by shot peening fatigue specimen of metastable austenitic steel to obtain a martensitic surface layer and a local heating by a laser beam to obtain an austenitic area in the layer. In order to investigate the response of the material sensor to overload and achieve different trigger thresholds, the thermal energy applied to create the sensor material and the geometry of the material sensors were varied. It is shown that the austenitized volume and the martensite fraction in the material sensor correlate with the phase of the eddy current signals. Starting from the martensitic surface layer, the phase decreases as the austenitized volume increases. If martensite formation takes place due to an overload, the phase increases as a result. To determine the threshold stress needed to trigger the material sensor, cyclic rotating bending tests were carried out on austenitic stainless steel 1.4301 (AISI 304). In step tests, the bending stress was gradually increased and subsequently ex-situ eddy current testing was carried out. The potential for predicting and classifying an overload is significantly greater with a higher applied thermal energy. Three different sensor geometries (rhombus, cross and ring) were employed in tests. In comparison, the rhombus-shaped material sensor provided the greatest potential for load history interpretation due to the significant phase change.

AB - Metastable stainless steels can be used as a load-sensitive sensor. In combination with an eddy current testing system, mechanical overloads of a component can be detected directly during operation. Material sensors were prepared by shot peening fatigue specimen of metastable austenitic steel to obtain a martensitic surface layer and a local heating by a laser beam to obtain an austenitic area in the layer. In order to investigate the response of the material sensor to overload and achieve different trigger thresholds, the thermal energy applied to create the sensor material and the geometry of the material sensors were varied. It is shown that the austenitized volume and the martensite fraction in the material sensor correlate with the phase of the eddy current signals. Starting from the martensitic surface layer, the phase decreases as the austenitized volume increases. If martensite formation takes place due to an overload, the phase increases as a result. To determine the threshold stress needed to trigger the material sensor, cyclic rotating bending tests were carried out on austenitic stainless steel 1.4301 (AISI 304). In step tests, the bending stress was gradually increased and subsequently ex-situ eddy current testing was carried out. The potential for predicting and classifying an overload is significantly greater with a higher applied thermal energy. Three different sensor geometries (rhombus, cross and ring) were employed in tests. In comparison, the rhombus-shaped material sensor provided the greatest potential for load history interpretation due to the significant phase change.

KW - austenitic stainless steel

KW - electromagnetic testing

KW - fatigue

KW - material sensor

KW - non-destructive testing

KW - overload monitoring

UR - http://www.scopus.com/inward/record.url?scp=85203019613&partnerID=8YFLogxK

U2 - 10.1007/s11665-024-09910-9

DO - 10.1007/s11665-024-09910-9

M3 - Article

AN - SCOPUS:85203019613

JO - Journal of Materials Engineering and Performance

JF - Journal of Materials Engineering and Performance

SN - 1059-9495

ER -