Answer:
HV = 372.4 KGf/mm^2

Step-by-step explanation:
given data:
minimum tensile strength = 1240 MPa
we knwo that
and brinell hardness number (HB} relation given as


1) relation betwen H.B and Rockwell is


2) relation between HB and Vickers hardnes HV is given as


HV = 372.4 KGf/mm^2