2016. Vol.19. No. 2, pp. 46-49
Influence of Wall Thickness of Thin-Walled Steel Pipes on Coercive Force Value
5> Method. For the experiment, sections of a tube were used as specimens; the required wall thicknesses for each specimen were achieved by lathe work. The technology of pipe manufacturing was taken into account, such as cold moulding of hot-rolled steel; cold moulding of cold-rolled steel; cold moulding of heat-treated rolled low-alloyed steel; heat-treated (annealed) pipe metal after moulding. For each specimen we measured Нс in longitudinal and transverse directions relative to the axis of the pipe.
Results. Measurements showed significant difference in the values of Нс for the pipes of the same steel grade but with different wall thicknesses, especially for thin-walled pipes (<5 mm). It is revealed that heat treatment (annealing) significantly reduces the Нс dependence on the metal thickness in comparison with the initial state of metal.
Conclusion. Wall thickness in the range of 1.5–4 mm significantly affects the value of Нс. When carrying out measurements on thin-walled tubes (<5 mm), it is necessary to take into account the pipe manufacturing technology. Heat treatment (annealing) of the pipes after moulding greatly reduces the influence of the pipe wall thickness on the coercive force value.
Key words: coercive force, pipe, wall thickness, heat treatment, annealing, steel, rolled steel
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