The 9 common sense of Rockwell hardness tester
1, Rockwell hardness elastic deformation effect on the hardness values: Rockwell hardness up to 0.5HR effect of elastic deformation on hardness value, so we must pay attention to the frame rigidity. The same, the machining accuracy of the elevating screw should be higher, can by itself weight of inserting the guide device, no obvious gap, in order to reduce the axial displacement, improving test precision.
2, Rockwell hardness test: must ensure that the applied force perpendicular to the test surface. The specimen for bending shape and other irregular shapes, must use special operation table corresponding to the type, and select the correct test device. For cylindrical specimens, must use the "V" type operation platform.
3. Stability test of Rockwell hardness tester: Rockwell hardness is often adjust the measuring lever, should maintain its stability. Available in one or two sets of good standard hardness blocks, regularly at the same hardness block test, with long-term stability test instrument, grasp their performance. The hardness test, standard hardness block near the school machine application and hardness values, make the test results more reliable.
4, Effect of loading rate Rockwell hardness on the hardness values: the effect of loading rate on the hardness values: when the main load Rockwell hardness meter application acceleration from 2 seconds to 12 seconds when the effects on the hardness, low hardness value is 0.2HRC, hardness 0.4HRC, high hardness of 0.6HRC.
5, The cone angle of the surface Rockwell hardness: head surface Rockwell hardness value increases with the diamond indenter cone angle. For 30N, 45N gauge, angle has great influence on the low hardness, little influence on high hardness. The 15N scale and 30N scale high values of hardness blocks almost no effect.
6, Rockwell hardness surface detection: detection of sample is generally flat, if the test was carried out on surface samples, and the curvature radius is small, the test results should be combined with correction. The convex surface samples, the hardness values decrease, should be amended amount plus; concave sample should be subtracted from the correction.
7, Digital Rockwell hardness boot does not show the reason: the power is disconnected, check whether the power line is conducted; fuse, fuse box out attachment replacement.
8, The surface Rockwell hardness meter installation note: open the box cover and around the baffle at the bottom of the fuselage, demolition of 4 fixed screws, can be placed in a vibration free hardness of dry clean and no corrosive gas and around the room. Install the hardness of the table should be strong, and do the diameter greater than 50 mm hole, for through screw.
9, The adjustable level of Rockwell hardness tester: adjustment should be the operation station installed in the screw at the top level, then the level on the operating table, adjust, make the hardness level within 0.2/1000.