Method for smelting nitrogenous Co-Cr-Mo alloy for surgical implanting through electroslag remelting furnace

Abstract

The invention belongs to the field of metallurgy and relates to a method for smelting nitrogenous Co-Cr-Mo alloy for surgical implanting through an electroslag remelting furnace. The method comprises the following steps: I, preparing an electrode and slag charge, welding a Co-Cr-Mo alloy stun rod and an artificial electrode together, and using a slag charge feeder to add the slag charge to be remelted; II, closing the furnace and filling nitrogen continuously for 2 minutes and then stopping nitrogen supply, and starting a cooling circulation system; III, arcing and slugging, and adopting a power, current, voltage and slag resistance comprehensive control method; IV, after slag charge adding, supplying nitrogen continuously; V, after the finish of an arcing period, starting a melting period, adopting a melting speed and slag swing control method, and stabilizing the melting speed to be 5kg / min; VI, adopting a stepped power reduction method during a hot top sealing process; and VII, cooling and demoulding inside the furnace. The Co-Cr-Mo alloy remelted by adopting the method is excellent in ESR ingot segregation control, N element is evenly distributed, the burning loss is less than 5 percent, the content of sulphur is lower than 10 ppm, and the ingot surface is free from the defect of slag troughs.

Description

technical field [0001] The invention belongs to the field of metallurgy, and relates to a method for smelting nitrogen-containing cobalt-chromium-molybdenum alloys for surgical implants in an electroslag furnace. Background technique [0002] Cobalt-chromium-molybdenum alloy has excellent mechanical properties, corrosion resistance and biocompatibility, and is an important material for orthopedic metal implants. The forged cobalt-chromium-molybdenum alloy is used in high-end cobalt-chromium-molybdenum artificial joints because of its more excellent mechanical properties. [0003] ISO5832-12:2007 for wrought cobalt-chromium-molybdenum alloy in the ISO cobalt-based alloy standard stipulates the standard composition of high-carbon and low-carbon alloys, as shown in Table 1: [0004] Table 1 chemical composition [0005] C Cr Mo Fe mn Si Ni N co low carbon ≤0.14 26.0～30.0 5.0～7.0 ≤0.75 ≤1.0 ≤1.0 ...

AI Technical Summary

Problems solved by technology

However, for electroslag remelted high-nitrogen-cobalt-chromium-molybdenum alloys, it is necessary to solve the high content of easily segregated elements (such as molybdenum) in the alloy and the segregation of the ingot caused by improper process selection. At the same time, it is necessary to strictly control the burning loss and The uniformity of its distribution puts forward higher requirements for the smelting process