Repair of Localized Damage in Steel by Heat Straightening

The use of heat straightening to repair damaged steel is finding increasing applications. However, there is one area in which little information can be found: the repair of localized damage. Described in this paper is a methodology for heat straightening repair of typical localized damage such as bulges or buckles. The keys to a safe repair are to (1) select proper heating patterns; (2) limit the heating temperature to 650°C (1,200°F) for carbon steels; and (3) limit jacking forces so that jacking stresses do not exceed 50% of yield at ambient temperature. Shown in this paper are recommended heating patterns for typical types of localized damage as well as methods for determining jacking forces. Experimental tests were also conducted where induced damage was repaired using various heating patterns. The data provide the basis for developing the most effective heating patterns. The use of procedures recommended here will result in a repaired member with strength properties similar to that of the original undamaged member, but with reduction in ductility.