Welding seam online annealing widely used in petroleum pipeline and other high quality steel pipe.
Steel pipe welding seam online annealing is an advanced technology to produce high strength steel pipe, through welding seam online annealing to eliminate residual stress of welding and improve the organizational structure, making the welding seam and it's heat affected zone and has the same organizational structure, toughness and strength performance as consistent with base metal.
Induction annealing equipment of steel pipe takes the induction heating coil as the main components for continuous welding pipe machine, it heats the seam which has just been welded and quenched, to above the critical temperature and anneals it (seam) to avoid the potential crack .The fine-crystal-particle structure produced by this process will guarantee a steel pipe tenacious that meet all standard requirements of the specification.
Complete set equipment of steel pipe welding seam online annealing consists of thyristor IF power supply, online annealing inductor, mechanical adjustment system and switch cabinet and integrative console.
1) Single power and frequency: 500/600KW,1-3KHZ
2) Thyristor IF power supply: SCM control, double PI ring adjustment for voltage and current, tank circuit uses tuning all-film capacitor and energy-efficient insulating transformer to match load.
3) Online annealing inductor and mechanical adjustment system consist of plane inductor with magnetic material, mechanical adjustment system and capacitor cabinet.
4) Switch cabinet consists of isolation switch, complex triip, DW17 automatic air switch and power grid isolation and step-up rectifier transformer.
5) Integrative console has IF power ON/OFF control, welding seam annealing temperature control and record files and so on function.

6) Redstar adopt swing angle tracking seam system for normalizing. The induction coils move in an orbit around the top of the pipe, precisely following every twist of the weld.