Page 221 - Materials Science and Engineering An Introduction

d 2 ] -

Formula for Hardness Number a 2P 2D 2 - 1

= pD[D HV = 1.854P/d 2 = 14.2P/l 2
HB HK

¶ Rockwell ¶ Superficial Rockwell

Load P P P 60 kg 100 kg 150 kg 15 kg 30 kg 45 kg

d 1 b
Top View d d 1 l Source: Adapted from H. W. Hayden, W. G. Moffatt, and J. Wulff, The Structure and Properties of Materials, Vol. III, Mechanical Behavior. Copyright © 1965 by John

Shape of Indentation Side View D d 136° t l/b = 7.11 b/t = 4.00 120°

Techniques carbide in. 1 @@@@ , 1 , 1 2 4 steel spheres a For the hardness formulas given, P (the applied load) is in kg, and D, d, d 1, and l are all in millimeters.

Hardness-Testing Indenter 10-mm sphere of steel or tungsten Diamond pyramid Diamond pyramid Diamond cone: , 1 e 8 16 diameter

Table 6.5 Test Brinell Vickers microhardness Knoop microhardness Rockwell and superficial Rockwell Wiley & Sons, New York.

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