The Effect of Applied Load on Hardness of Steels

Abstract

Hardness measurements can simple, but very useful provide materials mechanical properties. This is atest that is extremely localized in volume and does not affect significantly the structural properties. Theaim of this article is to highlight on influence of the applied load forces to the hardness measurementresults. In engineering practice it is generally the most widely used method of measuring the Vickershardness. This method has a variability of the loading forces in a wide range from nano/micro up tohigh loads in hundreds N. There is a well-known plastic material response, therefore, were taken intoaccount several steels commonly used in technical practice S355 NL+N, 316LVM, 34CrMo-4. Wheninterpreting the results should always point out to the value of the load. In common engineering practiceleads to confusion, or to comparing the hardness of the material obtained at different loads. Thisproblem is quite often occurs at nowadays and needs to be solved. Focus should be not only in termsof results depending on the load, but also from a statistical perspective of scattering measurements atvarious loads. Generally, in the technical practice is discussed independence measurement results ofVickers hardness on applied load, due geometric similarity of indents. When is used different forcesthere is a changed of the hardness results. This phenomenon is known as a size effect. This effect isgenerally related to each mechanical testing of materials. However, engineering practice getting intoconflict with this effect.

Mill Scales Blended Polymer Composites For Electrical Insulation Application

“…So, it can be derived from the microscopic observation that a critical concentration is required to achieve a homogeneous composite. After, optimizing iron oxide concentration in the mother polymer solution we tried to understand its surface homogeneity by using atomic force microscope (AFM) [15,16] and mechanical strength by measuring hardness value [17]. AFM is a technique used to map 3D images of surface roughness of a sample surface of interest.…”

“…The coarser grains images with surface The HV number is then determined by the ratio F/A, where F is the force applied to the diamond in gramsforce and A is the surface area of the resulting indentation in square millimeters. A can be determined by the formula [17].…”