Effects on Powder Metallurgy Steel Forgings properties
The effects on the mechanical properties of the parts of steel subjected to a heat treatment of the powder metallurgy (P/M) were given. Three powders, AISI 4650 and modified powders of AISI 4600 mixed with graphite to pay to 4640 the composition, and powders it AISI 4650, were made compact in preforms and heat forged in a hot and closed matrix. The studied variables were the density of preform, method of lubrication, preforms binder (time, temperature and atmosphere), forging the pressure (tsi 20 and 40) and the temperature (1850F, 2000F and 2200F), and forging the report/ratio (0.85 and 0.95). Relationship between porosity connected together and the porosity of total for the various densities of preform was given. A density higher makes the temperatures required compact of agglomeration due to the restricted mobility of reducing gases in the pores. The lubrication of wall of matrix was comparable with mixed lubrication, and it simplified operations of agglomeration of mixture and powder preform.