Precision casting pickling technology: Precision casting high-frequency welding is to use the skin effect and neighborhood effect of alternating current to roll the steel coil into a cross-section round tube blank. Rotating a group or a group of resistors (magnetic rods) forms an electromagnetic induction loop inside the tube near the center of the induction coil. Affected by the eccentricity and proximity effect, a strong concentrated heating effect is generated at the edge of the tube opening, so that The edge of the weld is heated rapidly, so that after the welding temperature is squeezed by the roller, the molten metal realizes the intergranular connection, and after cooling, a firm butt weld is formed.

The high-frequency welding of precision castings is based on the electromagnetic induction principle of the AC charge in the conductor, the adjacent effect and the eddy current heating effect. The billet at the edge of the weld is locally heated to a molten state, and the butt weld is realized by the extrusion of the roller. Intercrystalline bonding, so as to achieve the purpose of welding. High frequency welding is induction welding (also called pressure contact welding), it does not require solder, nor does it require solder, the welding heat affects a narrow range, the welding shape is beautiful, the welding mechanical performance is good, and the welding mechanical performance is good, so it is obtained in the production of steel pipes. It is very complicated to complete a precision casting in a wide range of applications. First, mold making → melting (temperature 1600°C) → pouring → vibration shell + cutting (cutting gate) → rough grinding (grinding) )→Pickling (desalination) (removal of oxide scale) (nitric acid), hydrogen fluoride.