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The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. [1] The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter ...
Vickers hardness test; Brinell scale This page was last edited on 16 November 2024, at 12:16 (UTC). Text is available under the Creative Commons ...
A variety of hardness-testing methods are available, including the Vickers, Brinell, Rockwell, Meyer and Leeb tests. Although it is impossible in many cases to give an exact conversion, it is possible to give an approximate material-specific comparison table for steels .
904L is an austenitic stainless steel.It is softer than 316L, [1] [2] and its molybdenum addition gives it superior resistance to localized attack (pitting and crevice corrosion) by chlorides and greater resistance reducing acids; in particular, its copper addition gives it useful corrosion resistance to all concentrations of sulfuric acid.
As a reference, the uncoated bearing steel had a hardness of Rockwell C 60. The average microhardness measured was 7,133 N/mm 2 for the uncoated steel and 9,571 N/mm 2 for the coated steel, suggesting the coating had a microhardness of approximately 34 percent harder than Rockwell C 60. A measurement of the plastic deformation, or permanent ...
Martensitic stainless steels can be high- or low-carbon steels built around the composition of iron, 12% up to 17% chromium, carbon from 0.10% (Type 410) up to 1.2% (Type 440C): [8] The chromium and carbon contents are balanced to have a martensitic structure.
Very hard steel (e.g. chisels, quality knife blades): HRC 55–66 (Hardened High Speed Carbon and Tool Steels such as M2, W2, O1, CPM-M4, and D2, as well as many of the newer powder metallurgy Stainless Steels such as CPM-S30V, CPM-154, ZDP-189. There are alloys that hold a HRC upwards 68-70, such as the Hitachi developed HAP72.
The hardness number is based on the applied force divided by the surface area of the indent itself, giving hardness units in kgf/mm 2. Microindentation hardness testing can be done using Vickers as well as Knoop indenters. For the Vickers test, both the diagonals are measured and the average value is used to compute the Vickers pyramid number.