"Правка" в данном случае - почти точно straightening. Хуже с импульсной. Если вбросить в Гугл "straightening" "welded structures", то попадаются главным образом "flame straightening" и "thermal straightening", но попалось и mechanical straightening (англоязычные сайты привожу наверху):

mechanical straightening, thermal straightening is the preferred method ... For complex welded structures, the welding induced distortion may not be easily ...
www.mrl.columbia.edu/Welding _Peng.pdf

material continues to be used for welded structures,. there will be a need to address this situation by ... Mechanical straightening requires large, expen- ...
www.esab.com/ESABHtml/ pdf/svetsaren/svetsaren_1_2003.pdf

commentary addressing heat and mechanical straightening repair work ...
bridges.transportation.org/sites/ bridges/docs/05%20Agenda%2046_Final.pdf

requiring corrective mechanical straightening ...
mmri.eng.mcmaster.ca/mmri/lectures/Nied.pdf
Effect of Flame and Mechanical Straightening on Material ...
www.shipstructure.org/list_reports.pl

Mechanical Straightening · Stress Relieving · Additional Services ... These stresses can also result from welding, fabrication and burning operations. ...
www.cflame.com/stress-relieving-services.htm

welded structures, deformations, thermal straightening, automation of technological processes 1.2. BRIEF DESCRIPTION (abstract): ...
www.paton.kiev.ua/eng/prop/2100.html

The EOPaton Electric Welding Institute (PEWI) - Department ...
for heat treatment of welds and products ( deposition of protective coatings, thermal straightening of distortions in welded structures, etc.); ...
www.paton.kiev.ua/eng/ inst/ntkstructure/deplist/d43.html

Flame straightening in metalworking industry ...
www.asr.ro/internationalcoferin.htm

Prof Schuler’s flame straightening forum showed delegates ...
www.wtia.com.au/pdf/D522 JF 34 final.pdf