Composite refrigeration method, in which semiconductor refrigeration was taken as core, combined with vapor-compression refrigeration,was firstly adopted to develop a kind of novel cooling gas generator used in cutting.

In order to eliminate the high content of ferrite structure in the outer layer with depth of 1 mm of the chilled cast iron camshaft produced in shell mould,an experiment with adding metal antimony into iron melt was conducted.

The "black line" defect found on chilled cast iron camshafts was analyzed metallographically and found that the microstructure of defect zone consisted of pearlitic matrix and D-type graphite.