New Process for Smelting Tin Bronze in Induction Melting Furnace
The induction melting furnace smelting process of tin bronze is called tin bronze. The alloy with copper and tin as the main components is called tin bronze. It is the oldest alloy. Most of the copper alloy artifacts unearthed in my country are made of tin bronze. Understanding and mastering the smelting process of tin bronze is important to ensure the quality of the alloy and reduce the burning loss of the elements. The commonly used smelting process is as follows. (1) The induction melting furnace melts the copper. Smelting in an induction furnace, without adding a covering agent, quickly melts the copper in an oxidizing atmosphere. Times deoxygenated. After the red copper is melted, it is deoxidized once. That is, 2/3 of the total amount of phosphorous copper is used for deoxidation, and its main purpose is to reduce Cu and O in red copper. (2) Add alloying elements. After one deoxidation, alloying elements are added. When the alloying elements to be added are tin, zinc, and lead, zinc can be added first, followed by tin-lead. The reason is that the melting point of zinc is higher than that of tin and lead, and zinc has a good deoxidizing effect. It can completely deoxidize the copper liquid after adding it first, so as to avoid the generation of SnO. The disadvantage is that the evaporation of zinc is larger. If tin is added first, SnO is often formed due to insufficient deoxidation of copper, which is difficult to remove. (3) Secondary deoxidation. After the alloying elements have been added, a second deoxidation is carried out. That is, 1/3 of the total amount of phosphorous copper is used for deoxidation, which plays the role of auxiliary deoxidation and refining. Inspection before furnace and temperature controlled casting. Important tin bronze castings should be inspected for fracture before the furnace, and the cross-sectional structure should be uniform and fine, without segregation, pores, and inclusions. The casting temperature of tin bronze is generally 1120～1200℃.
