It concerns the requirements relating to the quality of the wheel centers in special alloy steel castings, in the normalized state, for wheelsets of railway traction vehicles and for which particularly high mechanical characteristics are required, to the manufacture of said wheel centers and the tests to be carried out for their acceptance. For wheel centers made of unalloyed or low-alloy steel castings, see UNI 6860-71; for rolled wheel centers of unalloyed steel and for rolled wheel centers of special alloy steel, see UNI 7175-73 and UNI 7176-73 respectively. When ordering, it must be specified whether the wheel centers are to be supplied raw or roughed, semi-finished or finished. Material: the wheel centers must be manufactured with alloy steel, killed, processed in an electric furnace and having, in the normalized state, a unit tensile strength of between 450 and 530 n/mm2 (46 and 54 kgf/mm2). Its designation is: 10 Ni Mo v4 UNI 7464-75. Contents of the analytical elements. Marking. Manufacturing. Shape and size. Tests: visual examination; tensile test; resilience test; chemical analysis; determination of the global gas content (if any); microscopic examination; impact test; measurement of surface decarburization depth; ultrasound control; radiographic examination; static balancing. Requirements table. Appendix a: ultrasound control. Appendix b: radiographic control. Source: unifer-unsider 008.
UNI 7464-1975 history
1975UNI 7464-1975 Cast special alloyed steel wheel centres for wheel sets of railway traction units. Quality, requirements and tests.