Patent ID: 11913105
Assignee: ZHEJIANG UNIVERSITY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 7:
8. The method for preparing a copper alloy according to claim 1, wherein the method is carried out according to the following steps:
(1) batching and melting: performing batching according to the copper alloy compositions, feeding into a melting furnace to fully melt, conduct sampling detection and analysis of oxygen content and alloying element content, and after supplementing and fully deoxidization according to the analysis results, introducing the melt into the holding furnace through the melting furnace internal guide groove;
(2) horizontal continuous casting: performing the horizontal continuous casting under the side of the holding furnace, installing at least one multi-channel water-cooled crystallizers under the side of the holding furnace, the crystallizers being provided with three groups of independent cooling units along the extraction direction of the primary billet to realize multi-channel water inflow and multi-channel water outflow, and adopting a reverse cooling method, i.e. water inflow at the cold end and water outflow at the hot end, to allow the first group of cooling units to be closest to the holding furnace; making the temperature of the water inlet of each group of cooling units lower than 20° C., and controlling the temperature gradient of the three groups of cooling units by the following method: the water flow V3 of the third group of cooling units and the primary billet cross-sectional area S are determined according to the principle of 0.5 L/(min·mm2)<V3/S<2 L/(min·mm2), and the water flow V2 of the second group of cooling units and the water flow V1 of the first group of cooling units are determined according to the principle of V1:V2:V3=1.5:1.2:1, to achieve the cooling capacity of the three groups of cooling units with different strengths to form a reasonable temperature gradient; providing electromagnetic induction coils on the outer walls of the water cooling jackets of the first and second groups of cooling units of the crystallizer to achieve electromagnetic stirring, the electromagnetic stirring method being rotary stirring, and the current frequency being set to 2 to 500 Hz; the primary billet cross-sectional area S being set to 2000 to 50 mm2, and the extraction speed and the primary billet cross-sectional area are determined according to the principle of 0.5 mm·min≤S/v≤20 mm·min; providing a water curtain spray cooling device within 1000 mm outside the outlet of the crystallizer to cool the primary billet, the spray device adopting an atomizing nozzle, and the nozzle interval being 10 to 20 mm, setting the number of nozzles according to the size of the billet, the distance between the nozzle and the surface of the billet being 10 to 50 mm, and the water pressure being 0.5 to 0.8 MPa;
(3) continuous extrusion: after peeling the as-cast primary billet obtained from horizontal continuous casting, directly performing continuous extrusion, preheating the extrusion die to 500 to 600° C., preheating the copper alloy as-cast primary billet to 700 to 750° C., and then entering the cavity of the extrusion die for extrusion, controlling the rotation speed of the extrusion wheel at 3 to 8 rpm, the extrusion ratio at 3 to 8, and the extrusion gap at 0.6 to 2 mm; performing a high-intensity cooling water spray at the outlet of the extrusion die to quickly cool the billet from high temperature to room temperature, the spray device adopting an atomizing nozzle, and the nozzle interval being 10 to 20 mm, setting the number according to the size of the billet, and the distance between the nozzle and the surface of the billet being 10 to 50 mm, the water pressure being 0.5 to 0.8 MPa; the material of the extrusion die being forged Ni-base superalloy, which contains 0.05 wt. % C, 15 wt. % Cr, 6 wt. % Mo, 5 wt. % W, 2 wt. % Ti, 5.5 wt. % Al, and Ni; performing process smelting of the superalloy through vacuum melting+electroslag remelting, and forming by hot forging and heat treatment after homogenization;
(4) cold working: carry out cold working of the billet after continuous extrusion according to product requirements, the pass deformation of cold working being 5% to 10%, and the cumulative deformation being 50% to 99%;
(5) aging annealing treatment: coiling the billet after cold working and placing in a bell-type heating furnace for aging annealing treatment, first placing the billet on the lining, and then hoisting to cover the lining after the heating furnace body reaches the preset temperature, quickly heating the billet, after reaching the preset holding time, lifting the furnace body by a crane to make the billet to cool down quickly, introducing the reducing atmosphere throughout the heat treatment process to avoid oxidation; determining the product aging annealing temperature and time according to the following principles: taking billet samples after cold working in several groups, annealing at 300, 350, 400, 450, 500, 550, 600° C. for 0.1, 0.5, 1, 2, 4, 8, 16, 24, 48, 99.6 h respectively; testing the Vickers hardness and conductivity of the samples, and calculating the product of the hardness number and the conductivity value, and taking the test temperature of the sample with the largest product as the product annealing temperature, and taking the test time of the sample with the largest product plus 0.4 as the product annealing holding time;
(6) inspecting and packaging, and leaving the factory.