Resist removal by using atomic hydrogen
The structures in service condition such as bridges, offshore structures and so on are always suffered the pulsating loads by moving vehicles, the waves, current or wind, etc. So, repair, reinforcement or reconstruction works by welding on these structures are done under the pulsating loads. In this paper, the weld cracking test under the pulsating loads is carried out and the deciding method of the solidification crack is proposed with consideration based on welding mechanics. (1) Under the pulsating loads, there is a possibility which the solidification crack initiates in the zone, where no solidification crack initiates from Trans-Varestraint cracking test. Therefore, deciding the solidification crack initiation under the pulsating loads from the resluts of Trans-Varestraint cracking test, the accuracy of evaluation is low. (2) The accumulation strain, ε_t, by which the weld metal was repeatedly applied at a short time from the liquidus to the solidus was proposed as a measure for deciding the solidification crack initiation under the pulsating loads. The solidification crack initiates when ε_t is larger than critical strain, ε_<cr>, which is the materials characterisation. (3) ε_t was expressed with the relative root gap opening displacement, Δδ, which can be easily measured before welding. Moreover, the practical deciding equation for solidification crack initiation under the pulsating loads using Δδ was derived. (4) For the case that the uniform pulsating loads are applied, the validity of the practical deciding equation was concretely shown.
- Journal of photopolymer science and technology
Journal of photopolymer science and technology 21(2), 293-298, 2008