TPT March 2010

T echnology U pdate

Weld demanding

Roller-hearth tube furnaces

treatment process from start to finish – including loading/unloading and coil stacking/ unstacking – is fully automated. The only manual process is attaching and removing the copper tube coils from the vessel used to purge the inside of the tubes. Ebner has a reputation for being on the cutting edge of technology, a reputation that was again proven by innovations developed especially for another customer, Buntmetall Amstetten. Coils or straight copper alloy tubes up to 7m in length enter a vacuum lock before proceeding into the heat treatment section, resulting in significant savings in process atmosphere. Alternatively, longer straight tubes can be processed continuously in this highly versatile furnace. Beyond the heat treatment section, the tubes pass through a jet cooler with a maximum cooling gradient of 200 K/min, reconfigured specifically for CuNi tube. But Ebner’s roller-hearth furnaces are not just for copper: Zeleziarne Podbrezová has profited from Ebner’s technology for processing seamless stainless steel tubes at temperatures up to 1070°C. Its in-house lab conducts extensive quenching research in a test furnace in order to perfect this process. The key to distortion-free tubes with a homogenous microstructure is twofold: 1) minimising premature cooling of the material as it leaves the furnace and 2) a two-metre long quench zone featuring jet cooling at a rate of 300 K/min. The company says with its state-of-the- art roller-hearth furnace facilities, consistent, high-quality tube has never been easier or more cost-effective to produce. Ebner Industrieofenbau GmbH – Austria

quality tubular parts

EVER greater quantities of high quality copper tubes are in demand, largely prompted by the increasing popularity of air conditioning systems. Poongsan Corporation is one of the companies that has invested in a Hicon ® roller-hearth furnace facility for drawn copper tube coils. At this facility, a charge stack comprises five carrier frames placed on top of one another, each holding one coil weighing a maximum of 300kg with a maximum outer diameter of 1,200mm. Reference charges of 170kg coils (tube dimensions of 9.52mm diameter x 0.35mm) achieve a throughput of 3.6t/h. Thanks to Ebner Hicon ® technology, the temperature scatter throughout the charge is less than ±1.5K by the end of the soaking zone. The result is that all charge material has a very uniform grain size and consistent mechanical properties. The gas-tight design of the furnace and cooler features vacuum locks at the inlet and outlet and ensures the lowest possible oxygen content in the process atmosphere, thus preventing discoloration of the copper tube. The process atmosphere, a mixture of 2% hydrogen and 98% nitrogen, ensures that all residual lubricants on the outside and inside of the tube are completely removed. The automatic “cold/hot” purge system purges each coil five times during the heat treatment process. This system ensures the lowest possible residual carbon and contamination inside the tube – even inner grooved tube. The entire heat

CylinWeld

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

Fax: +43 73268 681000 Website: www.ebner.cc

CUTTING I COLLARING I WELDING technologies for processing tubular parts

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

See you in Düsseldorf! Visit us Stand 6 A 49

The Hicon ® roller-hearth furnace facility

109 9.12.2 09 21.42 ›

www.read-tpt.com larikka2.indd 2

M arch 2010