| Partner: Wojciech Macek |
Ostatnie publikacje
| 1. | Podulka P.♦, Macek W.♦, Zima B.♦, Kopeć M., Ricardo B.♦, Achtelik H.♦, Fracture surface topography measurements analysis of low-alloyed corrosion resistant steel after bending-torsion fatigue tests, Precision Engineering, ISSN: 1873-2372, DOI: 10.1016/j.precisioneng.2024.07.002, pp.1-34, 2024 Streszczenie: In this paper, an assessment of a topography measurement method for fracture surfaces of 10HNAP steel after bending-torsion fatigue tests was performed. Surface roughness was measured by using a non-contact Focus Variation Microscopy (FVM) technique in which the non-measured points (NMPs) and outliers (spikes) were removed by the application of general methods. The results revealed, that the optical measurement method introduced variations in the high-frequency errors, considered as noise within the selected bandwidth. Therefore, the minimization of the high-frequency noise (HFN) was proposed based on an extensive examination of ISO 25178 roughness parameters. Additionally, a general S-filter was applied, as recommended by international standards and commercial software. It was used to identify and remove noise from the measured data after pre-processing. Consequently, levelling and eliminating of NMPs and spikes was successfully performed. Subsequently, the results obtained by using various filters were compared to further assess the impact of different filtration bandwidths. Finally, the proposed procedure was validated by implementing different general functions, such as autocorrelation (ACF), power spectral densities (PSD), and texture direction (TD). It was concluded, that coupled characteristics, including profile and areal measurements, should be studied simultaneously since they are necessary to analyze the fracture surfaces comprehensively. Słowa kluczowe: bending-torsion fatigue ,surface topography ,roughness ,non-measured points ,outliers ,high-frequency noise,measurement errors Afiliacje autorów:
|  | 200p. | ||||||||||||||||||
| 2. | Macek W.♦, Kopeć M., Laska A.♦, Kowalewski Z. L., Entire fracture surface topography parameters for fatigue life assessment of 10H2M steel, Journal of Constructional Steel Research, ISSN: 1873-5983, DOI: 10.1016/j.jcsr.2024.108890, Vol.221, No.108890, pp.1-11, 2024 Streszczenie: In this paper, the entire fracture surface approach was used to assess an effect of 280,000 h of exploitation under internal pressure of 2.9 MPa and high temperature of 540 °C on the fatigue response of 10H2M (10CrMo9–10) power engineering steel. The mechanical testing was carried out on the hourglass specimens produced from the as-received, unused pipeline and the same material after long-time exploitation. The uniaxial tensile tests were performed to establish the stress amplitude for subsequent force controlled, fatigue testing in the range from ±250 MPa to ±400 MPa under the frequency of 20 Hz. Since the exploited 10H2M steel was characterized by significantly lower mechanical properties, different damage mechanisms responsible for specimen failure were revealed through fracture surface analysis. The fracture surface topography evaluation was performed with a 3D non-contact measuring system. It was found, that the exploitation state has a strong impact on the fatigue life and fracture characteristics since the significant drop in lifespan of about 300 %–400 % was found for the material after prolonged service. Finally, the proposed surface topography parameter was related to the stress amplitude in order to estimate the fatigue life for the steel in question. Słowa kluczowe: fatigue , 10H2M steel , Mechanical properties , Surface topography Afiliacje autorów:
| | 140p. |