Operation has now restarted at ABS Luna’s ONA (ON-line Annealing) chamber, which had been down for major modifications, including doubling chamber’s length. The unit is now capable of accepting and processing up to 50-meter long bars.
First in the world, directly on-line annealed, quenched and tempered bars were initially produced in autumn 2001. Production was then suspended because of the limited hourly capacity of ONA chamber first stage, due to its 24-meter length.
ONA chamber is a key component of ABS Luna, the Danieli ECR® Endless Casting Rolling specialty steel plant, which has been in operation since the end of 2000. Located in line with the cooling bed, it consists of a gas-fired walking-beam furnace where specialty steel bars remain for a given amount of time in order to complete many of the on-line heat treatments already started in the mill. One of ABS Luna plant’s major technological benefits is the possibility to perform on-line heat treatments, eliminating or substantially reducing off-line treatments.
The 500,000-tpy plant produces endlessly rolled (directly from liquid steel) and in-line heat-treated 20- to 100-mm diameter round bars, 40- to 100-mm square bars and 15- to 50-mm diameter bar-in-coils, in specialty and stainless steel qualities.