| 摘要 |
Method of fabricating a steel part (5) by powder metallurgy, characterized in that: - a prealloyed powder (7) is prepared having the composition desired for said part, except regarding the contents of O and N and, optionally, of C, having contents of O and N of at most 200 ppm, and having an Mn content of 0.4 to 2% by weight and a Cr content of less than or equal to 3%; - the powder (7) is placed in a container (1), the walls (2, 3) of which define a space (4), the shape of which corresponds to that of the part (5), a getter (6) being at the periphery of the powder (7), said getter (6) having the ability, at high temperature, to absorb and reduce CO and to absorb nitrogen, and the container (1) is placed under vacuum then sealed; - the container (1) and the powder (7) are brought to a temperature that leads to a sintering of the powder (7) and a densification of said power (7) that does not exceed 5%, an emission of nitrogen and of CO from the powder (7) and the absorption thereof by the getter (6); - a densification of said powder (7) is carried out by hot isostatic pressing in order to obtain said part (5); - said part (5) is separated from the container (1) and from the getter (6); - a scalping, a heat treatment and a machining of said part (5) are carried out. Steel part thus produced. |
