| 摘要 |
1443015 Sintered iron with austenitic surface SCHWABISCHE HUTTENWERKE GmbH 28 Nov 1973 [29 Nov 1972] 55153/73 Headings C7D C7F and C7U A sintered iron part with a surface layer only of an austenitic structure is preferably formed by diffusing austenite forming elements such as Mn, Ni or Cu into the surface. Diffusion may be effected into the green compact during sintering or into the sintered compact and the compact may then be cold worked. The green or sintered compact is preferably packed in a granular mixture up to 5 mm. particle size comprising a carburizing agent e.g. carbon, a thermally dissociating carbonate e.g. BaCO 3 , a halogen salt e.g. NH 4 Cl, an inert material e.g. SiO 2 or Al 2 O 3 and an austenite forming element e.g. Fe-Mn. Alternatively the iron compact may be sintered in a closed chamber out of direct contact with the mixture containing the diffusing elements and sintering is effected at 1000-1300‹C in an inert atmosphere or in vacuum. |
