What Are the Copper Tube Processing Methods?

There are many processing methods for copper tubes, but they can be summarized into two categories: hot processing and cold processing. For example, methods such as extrusion to make tube billets and oblique rolling and perforation are all to heat the tube billets to a temperature far above the recrystallization temperature of copper for deformation processing to obtain tube billets. The tube billets are made into pipes by cold rolling and cold drawing at room temperature. This traditional process has been used for many years. The extrusion billet feeding method is still in use. This is a traditional copper tube billet feeding method. Its production process is to melt electrolytic copper into solid round ingots, then heat it to above 850 in a heating furnace, and extrude it into tube billets one by one in the extruder, and then cold roll or multi-pass linear stretching to the tube billet required for disc stretching.

Extrusion is divided into high extrusion ratio and low extrusion ratio, both of which have refined grain structure and good surface quality. The tube billets extruded with high extrusion ratio are smaller in size and thinner in wall thickness, and can be directly processed on a continuous direct machine or a disc stretching machine; low extrusion ratio extrusion can use large ingots to extrude large-size tube billets, and then use a cold rolling tube mill for extension processing. For ingots of the same size and specifications, high extrusion ratios require a larger extrusion tonnage, and the tolerance of the extruded tube wall thickness is large.

At present, the continuous casting and rolling billet feeding method is very popular in China. This is a new billet feeding method that emerged in the 1990s. Its production process is to cut the horizontally cast hollow tube billet to a fixed length and then directly send it to the three-roll planetary tube rolling mill to roll out a smaller diameter thin-walled copper tube. Since the three-roll tube rolling mill can make the rolled copper tube non-rotating, it is easy to roll it into a coil online. Its characteristics are short production process, elimination of reheating and extrusion processes, and it has advantages in saving energy, reducing equipment investment, and reducing costs.