Manufacturing process for casting parts, such as motorbloecke, the thin walls and massive, void-free parts

摘要

Complex castings, such as cylinder blocks, are produced by casting ion contg. 3.6 - 3.8 % C, 2.8 - 3.2 % Si, about 0.4 % Mn, and up to 0.01 % Mg, at 1420 - 1450 degrees C; the cooling conditions are chosen depending on the wall thickness of the product in such a manner that the initial cooling rate is 10 - 14 degrees C/sec. By this meyhod, the wall thickness of e.g. a cylinder block can be reduced to 3 mm, whereby the total weight is reduced by 20 - 40 %. The formation of shrinkage voids and pores is avoided without using risers. The amt. of the spheroidisation modifiers is reduced. The casting can be easily worked mechanically.