TPT May 2010

W elding T echnology

Weld demanding

High frequency induction welding

THE induction high frequency welding method is a key process technology for the production of ferrous and non-ferrous tubes with a diameter range from a few millimetres up to 26" at wall thicknesses up to 25mm, for a variety of applications. Due to the growing product spectrum of tube and pipe mills, flexible welding systems are increasingly essential. SMS Elotherm’s welders accommodate a broad range of new materials and their alloying elements, particularly high strength steels and stainless steels, in a wide variety of dimensions. Through the optimum configuration of system parameters and welding frequencies, a single induction welder reliably produces high quality weld seams. The quality of the welding seam produced is dependent on a variety of parameters,

including material quality, material presentation, welding angle, impeder (ferrite quality), and frequency. Considering the influenceof the frequency on the seam quality, higher frequencies are generally to be preferred for small steel tubes and thin walls. For wall thickness greater than 4mm, lower frequencies below 150kHz are favoured. The required impeder-system concentrates the current flow in the strip edges and increases the efficiency of the welding process. The impeder has to match in diameter and length with the given tube size, and should have the maximum possible values for saturation flux density and amplitude permeability. SMS Elotherm has more than 70 years of experience as a supplier of complete

quality tubular parts

induction systems for an array of applications in the tube and pipe industries. To help tube and pipe makers improve their energy efficiency, SMS Elotherm develops and builds state-of-the- art converters (power supplies) for induction systems. SMS Elotherm GmbH – Germany Fax: +49 2191 891 726 Email: info@sms-elotherm.de Website: www.sms-elotherm.de

Fully automatic welding process without filling wire Welding takes place from inside leaving root outside For tubular parts either with saddle or straight weld

Tube welding with induction technology

Chicago area tube mills opt for EFD Induction Weldac

EFD Induction has delivered two of its Weldac 600kW high frequency induction IGBT (insulated gate bipolar transistor) tube welders to tube mills in the Chicago area. Both systems replaced older vacuum tube technology in existing tube mills. The tube producers will use the EFD Induction Weldacs to weld tube to customer and industry standards. Both Weldacs delivered can use contact welding or induction coil welding methods. Commenting on the delivery, Mark Andrus of EFD Induction in the USA said, “The customers have chosen EFD Weldacs based on the welders’ high efficiency, uptime performance, and excellent EFD Induction customer support. In addition, these customers now have reported gains in weld quality.”

The EFD Induction Weldac 600 high frequency tube welders have a single footprint layout, automatic load matching, and customised control packages to offer a wide range of operational flexibility. The Weldacs use of IGBT for high frequency switching allows for maximum ruggedness in the area of power electronics for solid- state high frequency tube welding. EFD states that, along with the good power factor rating, high electrical efficiency and high current handling capabilities of the Weldac, tube production and quality can be increased. EFD Induction Inc – USA Fax: +1 248 658 0701 Email: sales@us.efdgroup.net Website: www.efd-induction.com

LARIKKA Collaring | Welding | Cutting

technologies for processing tubular parts

Tel: +358 20 7121 444 Fax: +358 20 7121 449 maarit.aalto@lacol.com www.larikka.com

Thank you for visiting us!

93 16.3.2010 15.46 ›

www.read-tpt.com

M ay 2010

thanksilm.indd 2