我厂生产的渔轮推进器用的料材是锰铁黄铜55－3－1,要求抗拉强度大于50公斤/毫米2,延伸率大于 20%,并作 15 × 12、 D=30毫米的冷弯试验,推进器加工后不得有渣眼、气孔、缩孔等缺陷。为提高劳动生产率,降低成本,我们采用了一型多铸方法,最高可浇四件,经二年多使用很为满意。 I plant the fishing vessel propeller material is ferromanganese brass 55-3-1, the required tensile strength greater than 50 kg / mm2, elongation greater than 20%, and for 15 × 12, D = 30 mm of cold Bend test, propeller processing may not have slag eyes, pores, shrinkage and other defects. To improve labor productivity and reduce costs, we have adopted a type of multi-casting method, the maximum pouring four, after two years of use is very satisfied.