experiment set-up Urheberrecht: © STB

Optimisation and improvement of the flame straightening process

Short description

The research project "Optimisation and improvement of the flame straightening process" OPTISTRAIGHT aims at the improvement of the manufacturing process for geometry achieving of elements and members out of structural steel, leading to a significant enhancement of the competitiveness of steel construction elements for the construction, crane, ship and ma-chinery industry. In the current situation the straightening of steel construction elements to achieve the required geometrical shape takes a huge part of the manufacturing costs. This is due to the uncertainty of the correct flame straightening process, its backgrounds and its effects. Straightening by cold forming is not a real alternative: the occurring forces during cold forming of complex steel members become too great and also occur micro cracking and toughness loss, especially in case of using HSS.

The technical background of flame straightening in the workshops of steel constructors is often based only on empirical knowledge if existing at all. However in scientific circles the mechanisms of flame straightening for different temperatures, holding times and steel grades may be partially present, but the transfer to complex steel structures, sections, stiffness and real (extended) geometries is missing. Also application techniques, flame straightening procedures and an insight parameter clarification in particular for high strength steels does not exist at all. This situation often leads to expensive and unsafe "try-and-error" processes.

From an economical view therefore the flame straightening process represents a huge uncertainty-factor resulting into additional cost margins. These additional costs could be avoided if better knowledge and optimised flame straightening routines would be available.

In the research project the metallurgical mechanisms of flame straightening are to be thoroughly clarified, transferred to complex structural elements (welded and rolled members) allowing for the desired geometry to fulfil the required tolerances, with special regard to high strength steels. Thereby a comprehensive insight knowledge on the flame straightening process is expected that does not only give confidence in the process but also leads to an extension of the flame straightening technique to complex structures where at present often expensive "try-and-error"-tests have to be performed until the result is satisfactory.

It is expected to gain simple means to fully predict the flame straightening process avoiding try-and-error-tests in advance. And the avoidance of detrimental material impacts or excessive energy input is expected as a result of the research work.

The research investigations are to be carried out by an experienced expert team incorporating universities, the steel construction industry and two European global players of the steel working industry. Modern research techniques, numerical simulations as well as experiments with advanced measuring devices will be performed.

Research program

European Commission - Research Fund for Coal and Steel (RFCS)


Duration of project

07/2007 - 06/2010

Contact person

Markus Feldmann