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Information × Registration Number 0211U013461, 0111U006667 , R & D reports Title The study of laser welding of root passes of thick-walled pipes made of steel X70. popup.stage_title Head Shelyagin Vladimir Dmitrievich, Кандидат технічних наук Registration Date 03-01-2012 Organization E.O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine popup.description2 Conducted testing technological approaches for laser one-and two-ray welding of butt joints and root joints in different spatial positions, which are aimed at improving the quality of connections and slow performance of the process of welding joints of pipelines. Welding seam root were performed on samples of steel H70 of dulling 4 ... 6 mm in different spatial positions. It was found that by using energy Nd: YAG-laser power of 4 kW Welding speed is between 30 ... 60 m / hr. Vertical size of joints exceeds the amount flowing through the blunting of the metal walls designed edges. With increasing angle or using a U-shaped design, this effect is reduced. Cast metal joints are fine-grained and is a mixture of different forms of ferrite. In ZTV existing structure of the upper beynitu of individual sections martensite. Found that when welding steel pipe in a horizontal position to reduce costs of protective gas (CO2) from 32 to 8 l / min. leads to improved formation of the upper roller and eliminate undercuts. The same effect leads to a transition from odnopromenevoho two-ray laser welding while maintaining linear energy unchanged. At a fixed power density odnopromenevoho speed laser welding in the down position and "on descent" are close. When welding "on the rise 'rate should be increased by 10 ... 15%, and when welding in a horizontal position - reduce by at least 10% relative to the speed of welding in the down position. To improve the conditions of penetration and the formation of sutures to protective carbon dioxide should add about 10 ... 12% oxygen. Two-ray laser welding of steel pipe can not only increase the depth of penetration, but also modify the thermal cycle process in a way that eliminates the tendency to form martensitic and beynitnyh structures in cast metal seams and ZTV. Thus, unlike the laser-arc welding, there is no significant increase in grain size, suggesting a satisfactory level of resilience connections from two-ray welding. Product Description popup.authors Бернацький Артемій Володимирович Вайц Дмитро Володимирович Лукашенко Андрій Германович Хаскін Владислав Юрійович Шуба Іван Володимирович popup.nrat_date 2020-04-02 Close