whether or unlegiertes graphitisches cast iron, especially for the manufacture of cylinder blocks, moulds and brake drums

摘要

An alloyed or unalloyed cast iron in which the graphite is present predominantly in the vermicular form contains in percentage by weight:- .Mg.0.005 to 0.06 .Ti.0.15 to 0.5 .A metal or metals.0.001 to 0.015 from Gp. IIIB of the Periodic Table according to Lange's "Handbook of Chemistry". The Group IIIB metal is generally cerium, but yttrium, lanthanum or mischmetall may also be used. The iron generally contains:- .C.2 to 4 .Si.1.5 to 3.5 .Mn.0.1 to 2.5 .P.up to 0.2 .S.up to 0.025 and may also contain:- .Ni.up to 36 .Cr.up to 1 .Mo.up to 2 .V.up to 0.5 although Cr, Mo, V and Mn may exceed these limits when the Ni content is sufficient to render the iron austenitic. Cu should not exceed 0.5% and Sn not exceed 0.03% when Mg is 0.04% or above, these limits increasing to 2% and 0.15% respectively as Mg falls to 0.02%. Pb should not exceed 0.1% and Sb, Bi, should not exceed 0.01% each. Zr has the same effect as Ti but recovery is low. The alloy is particularly suitable for cylinder blocks and heads, brake drums and other automobile parts, rolls, ingot moulds, heat treatment pots, and machine components generally. The Group IIIB metal may be added to the bath in metallic form or as a reducible compound such as the oxide.