Obrabotka Metallov 2013 No. 1

ОБРАБОТКА МЕТАЛЛОВ № 1 (58) 2013 31 МАТЕРИАЛОВЕДЕНИЕ Evaluation of operational properties of zinc coating on couplings of tubing pipes I.A. Chizhov, V.V. Berezovskaya, A.V. Makarov, Y.V. Khudorozhkova The application of protective coatings is one of the promising directions of prolonging the life of a threaded connection “pipe-coupling” of tubing pipes for oil production. The coating must have high operational properties. The aim of the research work was to compare the properties of zinc coatings, obtained by different methods, to estimate their reliability. We have studied the operational properties of galvanic, thermo-diffusion and hot dip zinc coatings on steel 45, 30G2, 37G2F and 37G2S varying the strength group. Thickness, uniformity, micro hardness and wear resistance of the coatings were determined. All measurements of the coating properties were conducted in accordance with the requirements of actual standards and methods. The research showed that zinc coatings of different application techniques had significant differences in stud- ied parameters, but their values within the same technology were virtually independent of the base metal. The hot dip zinc coating had the largest thickness ( ∼ 100 microns), but less uniform. No differences in the adhesive prop- erties of zinc coatings of different application techniques were identified. For all coatings the degree of adhesion to the base metal was high. The thermo-diffusion coating had a significantly higher hardness compared to hot and galvanic ones due to the presence in it of intermediate phase δ 1 and it had the highest wear resistance. Key words: a threaded connection “pipe-coupling”, zinc coating, adhesion, micro-hardness, wear resistance. Сборник научных трудов. Екатеринбург: УрФУ. – 2012. – С. 303–306. 4. Чижов И.А . Анализ технологии термодиф- фузионного цинкования муфт для НКТ на ОАО «ПНТЗ» // ХI Международная научно-техническая уральская школа-семинар молодых ученых – метал- ловедов: Сборник научных трудов. Екатеринбург: УрФУ. – 2010. – С. 237–239. 5. ЧижовИ. А., ПачколинаП.А., БерезовскаяВ.В . Влияние технологии цинкования трубных сталей на структуру и свойства покрытий // Инновации в ма- териаловедении и металлургии. Материалы II меж- дународной интерактивной научно-практической. конференции. Екатеринбург: УрФУ. – 2012. – С. 106–109.