| 摘要 |
PURPOSE:To obtain a sintered alloy having wear resistance comparable to conventional materials and yet scarcely causing wear to opposite materials by infiltrating, after heat treatment, lead into the porosity of a sintered alloy with prescribed density made of high speed steel having a specific composition. CONSTITUTION:The powdered high speed steel consisting of, by weight, 0.2-3% C, 0.1-0.8% Si, 3.5-4.5% Cr, 1.2-15% W, 0.5-10% V, 3-19% of 3-10% Mo and/or 4-17% Co and the balance Fe is compacted and sintered to form a sintered compact having a density ratio of 75-85%. Subsequently, the sintered compact is oil-hardened, which is put into a lead-infiltrating furnace so as to infiltrate 15-30wt% molten lead into the porosity of the sintered compact at a prescribed pressure by means of nitrogen gas. Furthermore, usually sintered compacts of high speed steel are subjected to tempering after hardening but, according to the above method, the necessity of tempering treatment is practically obviated because the lead-infiltrating temp. corresponds to the tempering temp.
|
