| 摘要 |
PURPOSE:To provide the manufacturing method of a screw for plastic molding, which has high rigidity and, at the same time, corrosion resistance and wear resistance. CONSTITUTION:A screw main body made of material, which requires neither quenching nor annealing and has high rigidity even after fusing treatment, is divided to longer direction into a plurality of divisions. To the respective divisions, spraying materials 15, 16, 17 and 18, the degree of anticorrosion and of abrasion quality of which are different from one another, are sprayed longitudinally and continuously so as to form spray coated layer on the surface of the screw main body. Next, by heating the resultant screw in an inert gas atmosphere furnace or a vacuum furnace, fusing treatment is performed so as to diffusion-bond the spray coated layer to the screw main body in order to produce the screw concerned. |
