Analysis of the bases of low-steel steel strengthening and selection of welding materials for multi-welded welding under the flux of pipes from steel 17G1S-U

Abstract

The information on the introduction of low-alloy steels of high and high strength during the
construction of main pipelines and other metal structures operating at negative temperatures is
analyzed, which is an effective way to reduce metal consumption. Data on the effect of the chemical
composition on the mechanical properties, the structure of the steels, and their propensity to
cracking are generalized. The influence of the thermal cycle of welding, the composition of welding
materials and other technological parameters of welding on the propensity to form cold cracks is
shown, which is caused by a combination of metallurgical, technological and constructive factors.
The results of studies of the toughness of weld metal on low-alloy steel of high strength grade
17G1S-U in the temperature range from minus 200C to minus 600C, welded with welding wires doped
with manganese, molybdenum, chromium, and nickel are presented. The propagation rates of cracks
and the critical strain rate of weld metal are given, the analysis of which allowed recommending the
welding wires Sv-08GM and Sv08MM for two-arc welding under the AN-60 main flux to ensure
equal strength with the base metal and high resistance of weld metal to formation and propagation of
cracks without preliminary Preheating before welding, which contributes to the expansion of the use
of 17G1S-U steel for the production of welded pipes of large diameter.