Detection Content

Detection Purpose: Test material Rockwell hardness number

Detection range: Oil pipeline, boiler, liquefied gas tank and other pressure vessels, metal and alloy products

The test method of Rockwell hardness (HR) is to press the diamond cone or steel ball into the metal surface, and apply two loads successively: initial load (usually 10kg) and total load (initial load plus main load) of 60, 100 and 150kg. The Rockwell hardness is obtained by the difference of the indentation depth of the two loads.            Rockwell hardness is divided into 15 types according to the selected indenter and load. HRA, HRC and HRB are most commonly used.            HRA is the hardness obtained by using 60kg load and diamond cone indenter, which is used for materials with high hardness. For example: thin plate, hard alloy, surface hardening, etc.            HRB is the hardness obtained by using 100kg load and 1.58mm diameter hardened steel ball, which is used for materials with lower hardness. For example: low and medium carbon steel, annealed steel, copper alloy, duralumin alloy, mild steel, non-ferrous metal, annealed steel, cast iron, etc.            HRC is the hardness obtained by 150 kg load and diamond cone indenter, which is used for materials with high hardness. For example: quenched steel, Quenched and tempered steel, etc.