Assessment of fluid wettability on internal imperfections measurement of rolled plates by Archimedes’ principle

Abstract

Archimedes’ principle is an alternative method for estimating internal imperfections. This study investigated the effect of fluid-metal interfacial behavior on the internal imperfections measurements based on Archimedes’ principle. Two carbon-steel plates were used, one with a punched surface by the depth of a sharp conical indentation. These punched indentations simulate surface undulations, which may cause incomplete filling of the valleys with the liquid, entrapping air and leading to measurement errors. Trapped air will be artificially counted as internal imperfections. To evaluate whether such a setback could affect gravimetric measurements, two liquids with different surface tension and density (deionized water and analytical-grade ethanol) were examined using flat and punched carbon-steel plates. According to the measurement technique procedure, the plates were weighed in air and in liquid, and measurements were repeated to assess repeatability. The determined internal imperfection for the flat plate was 0.06±0.01% in water and 0.06±0.02% in ethanol (one-way ANOVA: F=0.05, P=0.821). The computed internal imperfection for the punched plate was 0.12±0.03% in water and 0.06±0.04% in ethanol (F=16.25, P=0.001), reflecting an absolute difference of 0.06 percentage points. The results indicate that the immersion liquid significantly influences Archimedes-based internal defect evaluation in the presence of acute recesses; however, no significant variation was detected for flat surfaces within the experimental variability. These findings affirm that, contingent on the sample's surface state, the liquid must be judiciously chosen, so that a liquid exhibiting a lower liquid-solid surface tension than water may be more advantageous.