CC BY
4
05.02.10
СВАРКА, РОДСТВЕННЫЕ ПРОЦЕССЫ И ТЕХНОЛОГИИ
DOI: 10.33693/2313-223X-2019-6-2-21-27
STUDY ON A-TIG WELDING ENERGY EFFICIENCY OF STAINLESS STEELS USING INDIVIDUAL FLUX-OXIDES
Part 1: EVALUATION OF THE A-TIG ARC ENERGY EFFICIENCY TO THE WELD DEPTH OF PENETRATION
Saidov Rustam Мannapovich, PhD, senior research of the Institute of Material ScUinces, SPA "Physics-Sun" Academy of ScUince of Uzbekistan. E-mail: saidov_r@yahoo.com
Komilova Durdona Rustamovna, senior research of the Institute of Material ScUinces, SPA "Physics-Sun" Academy of ScUince of Uzbekistan. E-mail: komilova78@mail.ru
Kusch Mario, Dr.-Ing., Department of Manufacturing and Welding Engineering, Chemnitz University of Technology. Germany. E-mail: mario.kusch@mb.tu-chemnitz.de
MayrPeter, professor, Dr., Department of Manufacturing and Welding Engineering, Chemnitz University of Technology. Germany. E-mail: peter.mayr@mb.tu-chemnitz.de
Hoefer Kevin, Dipl.-Ing., Department of Manufacturing and Welding Engineering, Chemnitz University of Technology. Germany. E-mail: kevin.hoefer@mb.tu-chemnitz.de
Abstract. This article presents the results of the study of activating oxide fluxes effects on the energy efficiency of the TIG welding arc (A-TIG) influence. This efficiency was estimated by the amount of energy spent by the arc (q) at the depth of penetration (P). It is revealed that the arc energy efficiency factor "Kepac" can be used as an indicator of the influence of arc energy on the efficiency of penetration of the welded metal, which is determined by the ratio of spent energy per unit of depth of penetration (q/P) at TIG and A-TIG welding. In accordance with the results of the research, it is observed an increase of the energy efficiency on the welding arc penetration capability of all individual oxides used as fluxes in A-TIG welding is observed. Among them, the greatest energy efficiency of the arc process on the penetration of CrNi18-10 steel is observed when oxides such as TiO2, SiO2, Cr2O3 and Co3O4 are used.
Key words: TIG welding, stainless steel, activating oxide fluxes, arc energy efficiency.
Introduction
One of the main parameters of the arc welding process of metal is heat input welding that facilitates welding bead formation and identification of quality and welding joints properties. Heat input (HI) is the ratio of the effective thermal power of the arc to the speed of its movement (welding speed) [1] and is determined by the following formula:
HI = q/Vw, (1)
where q - arc energy [W or J/s]; Vw - welding speed [cms-1]. Arc energy (q) [W] calculated as following:
q = IUn, (2)
where I - welding current, [A]; U - arc voltage, [V]; r| - effective coefficient of usefulness of electric arc - the part of electric arc energy which is spent on metal melting.
The increase of efficiency of arc energy transfer to welded constructions contributes to the production of quality welded joints at lower energy usage. Similar effect is achieved with TIG
welding with activating fluxes (A-TIG) which allows to reduce the welding arc energy up to 2-6 times in comparison with the usual TIG welding [2; 3].
If at TIG welding the arc energy is mainly consumed for heating and melting of the welded construction and losses to the environment [4], then at A-TIG welding the distribution of the arc energy changes (Fig. 1) due to the usage of activating flux (Ef).
In this case, the energy related with the usage of the activating flux consists of the energy spent to the flux melting (Emf) and released as a result of decomposition and dissociation of compounds and flux elements (Edf):
Ef = E -
f mf
(3)
where Emf - energy spent for flux melting; Edf - energy released as a result of decomposition and dissociation of compounds and flux elements.
The important indicator of A-TIG welding is the energy efficiency of welding arc in the depth of penetration of welding plate. This efficiency indicator can be the energy loss to forming
E
05.02.10
Materials and Methods
As stainless steel for conducting research it was used the steel CrNi18-10 (Table 1) as the plates of 60 x 150 mm size and 4 and 5 mm thick.
TIG welding regimes: Welding was conducted in the lower position of the arc length in 2 mm, electrode diameter: 3.2 mm, electrode grinding angle: 30°, welding current: 100 A (for plates,
4 mm thick) and 200 A (for plates, 5 mm thick), welding speed: 20 cm/min (for plates, 4 mm thick) and 30 cm/min (for plates,
5 mm thick), shielding gas: argon 10 l/min., Inflating from the back side of the welding bead: 5 l/min.
As the flux it was used individual oxides as MgO, SiO2, TiO2, Cr2O3, WO3 m Co3O4. Fluxes were used as pastes which were produced by mixing of powder oxides (with particles sizes no more than 100 mkm) with alcohol 1: 1 weight ratio, which provided a flux layer on the surface of 0.24 mm thick plates. The paste layer was applied using a brush on a half plate with a width of up to 10 mm (Fig. 2).
The instrument microscope was used to test the morphology of the welding beads which is characterized by the width (W), the depth of penetration (P) and the ratio of the depth of penetration to the width (P/W) of the welding beads.
Table 1
Chemical composition of the steel CrNi18-10 (1.4301) [DIN EN 10088-3]
C Si Mn P S N Cr Ni
<0.07 <1.0 <2.0 <0.045 <0.015 <0.11 17.0-19.5 8.0-10.5
Results and Discussions
For conducting the research on influence of thermodynamic and physical-chemical properties of individual fluxes-oxides to the energy efficiency of penetration capability of the welding arc by the different linear energy of A-TIG welding used the results carried out by TIG and A-TIG welding of the stainless steel CrNi18-10 with thickness in 4 and 5 mm [5].
In tables 2 and 3 showed the electrical parameters with TIG and A-TIG welding using individual fluxes-oxides of the steel CrNi18-10, 4 and 5 mm thick.
Table 2
Electrical welding parameters of TIG and A-TIG welding of the steel CrNi18-10 of 4 mm thick
№ Electrical welding parametres
TIG (without flux) A-TIG (with flux)
Welding current I, A Arc voltage U, V Arc energy q, W Flux Welding current I, A Arc voltage U, V Arc energy q, W
1 104.69 7.78 489 MgO 104.69 8.68 545
2 103.93 7.57 472 SiO2 103.93 7.81 487
3 103.74 7.78 484 C^2O3 103.74 8.28 516
4 103.67 7.91 492 TÍO2 103.67 7.89 491
5 103.54 7.77 482 WO3 103.54 8.12 505
6 103.42 7.76 482 C°3O4 103.42 8.04 499
WELDING, RELATED PROCESSES AND TECHNOLOGIES
the unit of surface area (HI/P) and the unit of depth of penetration (q/P). The higher energy efficiency of the arc energy effects on its penetration capability while the lower values of these indicators are shown.
Fig. 1
101
Fig. 2
STUDY ON A-TIG WELDING ENERGY EFFICIENCY OF STAINLESS STEELS USING INDIVIDUAL FLUX-OXIDES PART 1: EVALUATION OF THE A-TIG ARC ENERGY EFFICIENCY TO THE WELD DEPTH OF PENETRATION Saidov R.M., Komilova D.R., Kusch M., Mayr P., Hoefer K.
Table 3
Electrical welding parameters of TIG and A-TIG welding of the steel CrNi18-10 of 5 mm thick.
№ Electrical welding parameters
TIG (without flux) A-TIG (with flux)
Welding current I, A Arc voltage U, V Arc energy q, W Flux Welding current I, A Arc voltage U, V Arc energy q, W
1 202.73 10.24 1244 MgO 202.73 11.72 1426
2 202.76 11.08 1347 SiO2 202.76 12.48 1519
3 202.19 11.11 1348 202.19 12.67 1538
4 202.20 10.21 1238 TiO2 202.20 10.99 1333
5 202.16 10.83 1313 wo3 202.16 11.46 1390
6 201.97 10.73 1300 C°3°4 201.97 11.22 1360
As shown by the results presented in tables 1 and 2, the arc energy of A-TIG welding is higher than arc energy of traditional TIG welding. The use of oxides at A-TIG welding increases arc energy at welding current of 100 A to 12%, and at current of 200 A to 15%. In this case, the width of welding beads (WATIG), performed welding using the fluxes-oxides (A-TIG) is narrowed compared to the width of the joints (WTIG)
the traditional welding (TIG), at the welding current of 100 A from 165% to 298%, and at the welding current of 200 A from 107% to 175%. The depth of penetration of A-TIG welding beads (PATIG), is increasing at the welding current of 100 A from 152% to 243% and at the welding current of 200 A from 153% to 247%, compared with the depth of penetration of welding bead (PTIG) of traditional TIG welding (Fig. 3).
Without
MgO
SiO2
CrA Fig. 3
TiO,
WO3
Co,O.
9
8
7
6
5
4
3
2
1
0
WELDING, RELATED PROCESSES AND TECHNOLOGIES
Dependence of the influence of the ratio of energies of A-TIG and TIG arcs (qATIG/qTIG) on the ratio of the width (WATIG/WTIG) and depth of penetration of welding beads A-TIG and TIG (PATIG/PTIG), is shown in Fig. 4. This dependence shows an increase in width and a decrease in the depth of penetration with an increase in arc energy a-TIG at a welding current value of 100 A. When welding at a current of 200 A, there is a slight narrowing of the welding beads and an increase in the depth of penetration to a certain
05.02.10
value of qATIG/qTIG and its subsequent decrease with an increase in the ratio of energies of A-TIG and TIG arcs.
Thus, it is revealed that the increase in the A-TIG arc energy reduces the efficiency of its action on the penetration capability at a current of 100 A. When welding at a current of 200 A, the efficiency of the penetration capability of A-TIG arc, with an increase in arc energy is firstly increased to certain limits, and then decreased (Fig. 4).
i^g/W,,, Paflg/Pflg
/
/ Y A
—
---
\
R2 = 0,546
• Pa,g/P,g(200 A)
♦ Wa,g/W,g(200 A) A Pa,g/P,g(100 A) ■ Wa,g/W,g(100 A)
\
R2 = 0,403
R = 0,203
R2 = 0,749
0,98 1,00 1,02 1,04 1,06 1,08
Qatlg^tlg
1,10
1,12
1,14
1,16
Fig. 4
Apparently, the difference between the effects of arc energy on the formation of welding beads at 100 A and 200 A is explained by the different mechanism of action of the fluxes. On small welding currents, the mechanism of action of activating fluxes-oxides can be connected with the physical processes proceeding in a welding arc [6-10], and at welding on high currents the mechanisms of action of fluxes connected with the chemical processes proceeding in a welding bath prevail [11; 12].
Study of the energy efficiency of the arc A-TIG using individual fluxes-oxides was estimated by the amount of arc energy spent on the depth of penetration (q/P). According to the obtained results (Fig. 5) when TIG welding steel CrNi18-10, there has been a reducing the consumption of the arc energy of A-TIG welding per unit depth of penetration at a welding current of 100 A on 184-309% and at a welding current of 200 A on 134-230% (Fig. 5).
As an indicator of the influence of arc energy on efficiency of the penetration of welded metal, the arc energy efficiency factor "K " was used, which was determined by the ratio
epac ' '
of consumption energy per unit of the depth of penetration (q/P) for TIG and A-TIG welding, and calculated according to the following formula:
Kepac = to/P>T,G /(4/P)at,G'
(4)
where Kepac - arc energy efficiency factor; (q/P)TIG - consumption of energy per unit depth of penetration (q/P) with TIG welding, W/mm; (q/P)ATIG - consumption of energy per unit depth of penetration (q/P) with A-TIG welding, W/mm.
The results of calculations of the arc energy efficiency factor (Kepac) are presented in Fig. 6. In accordance with these results, there is an increase in the energy efficiency of the action on the penetration capability of the welding arc of all used individual oxides for welding a-TIG. Among them, the greatest arc energy efficiency action at welding of CrNi18-10 steel, observed in the application of oxides such as TiO2, SiO2, Cr2O3 and Co3O4, which more than twice increase the energy efficiency of the arc penetration capability (Kepac > 2), compared with traditional TIG welding.
STUDY ON A-TIG WELDING ENERGY EFFICIENCY OF STAINLESS STEELS USING INDIVIDUAL FLUX-OXIDES PART 1: EVALUATION OF THE A-TIG ARC ENERGY EFFICIENCY TO THE WELD DEPTH OF PENETRATION Saidov R.M., Komilova D.R., Kusch M., Mayr P., Hoefer K.
800
■ tig (100 a) ■ a-tig (100 a) ■ tig (200 a) ■ a-tig (200 a)
616 489 667 + 667 + 616 492 650 rt- 644 644
rin H I In 1 11 In H ll 11 ll 262 mi In i 174
o-
<u 200
MgO
SiO2
C^O,
TiO2
WO,
Co,O.
Fig. 5
o
MgO
SiO2
TiO2
WO,
Co,O.
Fig. 6
Cr2a
WELDING, RELATED PROCESSES AND TECHNOLOGIES
Conclusions
An energy efficiency of a welding of stainless steel CrNi18-10 by traditional TIG welding and A-TIG welding using activating individual flux-oxides, showed the decrease in energy consumption during A-TIG welding per unit depth of penetration at welding current of 100 A on 184-309%, and at a welding current of 200 A on 134-230%.
The authors of this paper found that as an indicator of the influence of arc energy on the efficiency of depth of penetration, one can use the arc energy efficiency factor "Kepac", which is determined by the ratio of energy consumption per unit depth of penetration (q/P) at TIG and A-TIG welding, and calculated by the following formula:
Kepac = (q/P)lIG/(q/P) ATIG'
In accordance with the results obtained, an increase in the arc energy efficiency factor of all individual oxides used as activating fluxes in A-TIG welding is observed. Among them, the greatest energy efficiency of the arc action on the penetration of CrNi18-10 steel is observed when using oxides such as TiO2, SiO2, Cr2O3 and Co3O4.
References list
1. Savytsky O.M. et al. Characteristics of Constructions and Reliability of Welded Structures in the Combined High-Pressure Vessels (in Ukrainian) // Research and Development in the Field of Oil and Gas. 2013. No. 2. Pp. 133-143.
2. Savytsky O.M., Savytsky M.M., Shkrabalyuk YM., Vuherer T., Ba-jic D.R. The Influence of Electric Arc Activation on the Speed of hea-
05.02.10
ting and the structure of metal in welds // Thermal Science. 2016. Vol. 20. No. 1. Pp. 239-246.
3. Thiago José Donega, Thonson Fereira Costa, Rosenda Valdés Arenci-bia, Louriel Oliveira Vilarinho. Comparison of thermal efficiency between A-TIG and conventional TIG welding // Welding International. 2016. Vol. 30. No. 4. Pp. 255-267.
4. Niles R.W., Jackson CE. Weld Thermal Efficiency of the GTAW Process // Welding Journal. January 1975. Res. Suppl. Pp. 25-32.
5. Saidov R.M., Kusch M., Mayr P., Hoefer K., Akhadov J., Komilova D., Mukhitdinov Z. Study of Influence of Oxide's Physico-Chemical Propertuis to the Formation Welding Beads During A-TIG Welding of Stainless Steels (in Russian) // Computational nanotechnology. 2016. No. 4. Pp. 10-20.
6. Ostrovskiy O.E., Krukovskiy V N., Buk B.B. at al. Influence on activating fluxes to the welding arc penetration property and energy concentration in anodic spot // Welding production. 1977. No. 3. Pp. 3-4.
7. Savitskiy M.M., Leskov G.I. Mechanism of electronegative elements on arc penetration property with tungsten cathode // Automatic welding. 1980. № 9. Pp. 17-23.
8. Bukarov V.A., Ishenko Yu.S., Erokhin A.A. Some characteristics of arc during steel 18-8 welding with oxidized surface // Welding production. 1975. No. 10. Pp. 3-4.
9. Leconte S., Paillard P., Chapelle P., Henrion G., Saindrenan J. Effect of oxide fluxes on activation mechanisms of tungsten inert gas process // Science and Technology of Welding and Joining. 2006. Vol. 11. No. 4. Pp. 389-397.
10. Simonik A.G., Petviashvili V I., Ivanov A.A. The effect of arcing contraction with the introduction of electronegative elements // Welding production. 1976. No. 3. Pp. 49-51.
11. Ishizaki K. et al. Interfacial Tension Theory on the Phenomena of Arc Welding // J. Japan Welding Society (JWS). 1965. Vol. 34. No. 2. P. 146.
12. Mills K.C., Keene B.J., Brooks R.F., Shirali A. Marangoni effects in welding // Philos. Trans. R. Soc. Math. Phys. Eng. Sci. 1998. Bd. 356. No. 1739. Pp. 911-925.
РЕЦЕНЗИЯ
на статью Р.М. Саидова, Д.Р. Комиловой, Марио Куша, Петера Майера, Кевина Хоефера «Исследование энергоэффективности процесса А-ТИГ сварки нержавеющих сталей с использованием индивидуальных флюсов-оксидов. Часть 1: Оценка энергетической эффективности А-ТИГ дуги на глубину проплавления»
В этой статье представлены результаты изучения влияния активирующих оксидных флюсов на энергетическую эффективность действия дуги при аргонодуговой сварке (А-ТИГ) нержавеющих стали Сг№18-10.
Целью данных исследований являлось выявление критериев оценки энергоэффективности сварочной дуги А-ТИГ на глубину проплавления свариваемого металла и энергоэффективность проплавляющей способности сварочной дуги при различных погонных энергиях сварки.
В работе в качестве индивидуальных оксидных соединений для исследования влияния на энергоэффективность проплавляющей способности сварочной дуги при ТИГ сварке нержавеющей стали использовались порошки оксидов (MgO, SiO2, ТЮ2, Сг203, WO3 и Со304). Флюсы использовались в виде паст, которые получали при смешивании порошков оксидов (с размером частиц не более 100 мкм) и наносились на поверхность кромок свариваемых пластин, толщиной 0,24 мм и шириной до 10 мм.
В качестве показателя влияния энергии дуги на эффективность проплавления свариваемого металла авторами этой
статьи был использован коэффициент энергоэффективности проплавляющей способности дуги Керас, который определялся отношением затрат энергий на единицу глубины проплавления (д/Р) при ТИГ и А-ТИГ сварке (Керас = (д/Р)Т|е/(д/Р)дТ|(.).
В результате проведенных исследований, авторами настоящей работы выявлено влияние индивидуальных флюсов-оксидов на энергоэффективность проплавляющей способности дуги (Керас). В соответствии с результатами исследований, наблюдается повышение энергоэффективности действия на проплавляющую способность сварочной дуги всех использованных индивидуальных оксидов в качестве флюсов при сварке А-ТИГ. Показано, что наибольшая энергоэффективность действия дуги на проплавление стали Сг№18-10, наблюдается при применении таких окислов, как ТЮ2, SiO2, Сг203 и Со304.
Работа выполнена на высоком научно-техническом уровне и может быть опубликована в открытой печати.
Доктор технических наук Р. Рахимов
ИССЛЕДОВАНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ ПРОЦЕССА А-ТИГ-СВАРКИ НЕРЖАВЕЮЩИХ СТАЛЕЙ С ИСПОЛЬЗОВАНИЕМ ИНДИВИДУАЛЬНЫХ ФЛЮСОВ-ОКСИДОВ. ЧАСТЬ 1 Саидов Р.М., Комилова Д.Р., Куш М., Майр П., Хоефер К.
DOI: 10.33693/2313-223X-2019-6-2-21-27 УДК 621.791.037
ИССЛЕДОВАНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ ПРОЦЕССА А-ТИГ-СВАРКИ НЕРЖАВЕЮЩИХ СТАЛЕЙ
С ИСПОЛЬЗОВАНИЕМ ИНДИВИДУАЛЬНЫХ ФЛЮСОВ-ОКСИДОВ
Часть 1: ОЦЕНКА ЭНЕРГЕТИЧЕСКОЙ ЭФФЕКТИВНОСТИ А-ТИГ-ДУГИ НА ГЛУБИНУ ПРОПЛАВЛЕНИЯ
Саидов Рустам Маннапович, канд. техн. наук; старший научный сотрудник Института материаловения НПО «Физика-Солнце» Академии наук Республики Узбекистан. E-mail: saidov_r@yahoo.com
Комилова Дурдона Рустамовна, младший научный сотрудник Института материаловедения НПО «Физика-Солнце» Академия наук Республики Узбекистан. E-mail: komilova78@mail.ru
Куш Марио, др.-инж. Департамента производства и сварочной техники Хемницкого технологического университета. Германия. E-mail: mario.kusch@mb.tu-chemnitz.de
Майр Петер, профессор, доктор; Департамент производства и сварочной техники Хемницкого технологического университета. Германия. E-mail: peter.mayr@mb.tu-chemnitz.de
Хоефер Кевин, инженер Департамента производства и сварочной техники Хемницкого технологического университета. Германия. E-mail: kevin.hoefer@mb.tu-chemnitz.de
Аннотация. В этой статье представлены результаты изучения влияния активирующих оксидных флюсов на энергетическую эффективность действия ТИГ дуги (А-ТИГ). Эта эффективность оценивалась количеством затраченной энергии дуги (q) на глубину проплавления шва (Р). Выявлено, что показателем влияния энергии дуги на эффективность проплавления свариваемого металла может служить коэффициент энергетической эффективности проплавляющей способности дуги Kepac, определяемый отношением затрат энергий на единицу глубины проплавления (q/Р) при ТИГ и А-ТИГ сварке. В соответствии с результатами исследований, наблюдается повышение энергоэффективности действия на проплавляющую способность сварочной дуги всех использованных индивидуальных оксидов в качестве флюсов при сварке А-ТИГ. Среди них, наибольшая энергоэффективность действия дуги на проплавление стали CrNi18-10, наблюдается при применении таких окислов, как TiO2, SiO2, Cr2O3 и Co3O4.
Ключевые слова: аргонодуговая сварка, нержавеющая сталь, оксидные активирующие флюсы, энергетическая эффективность действия дуги.
Литература
1. Савицкий О.М. и другие. Характеристика конструкций и надежность сварных конструкций в сборных сосудах высокого давления (на украинском языке) // Исследования и разработки в области нефти и газа. 2013. № 2. С. 133-143.
2. Савицкий О.М., Савицкий М.М., Шкрабалюк Ю.М., Вухерер Т., Баич Д.Р. Влияние активации электрической дуги на скорость нагрева и структуру металла в сварных швах // Тепловая наука. 2016. Т. 20. № 1. С. 239-246.
3. Thiago José Donega, Thonson Fereira Costa, Rosenda Valdés Arenci-bia, Louriel Oliveira Vilarinho. Comparison of thermal efficiency between A-TIG and conventional TIG welding // Welding International. 2016. Vol. 30. № 4. Pp. 255-267.
4. Niles R.W., Jackson C.E. Weld Thermal Efficiency of the GTAW Process // Welding Journal. January 1975. Res. Suppl. Pp. 25-32.
5. Саидов Р.М., Кущ М., Майр П., Хофер К., Ахадов Ю., Комилова Д., Мухитдинов З. Исследование влияния физико-химических свойств оксида на формирование сварных швов при A-TIG-свар-ке нержавеющих сталей // Computational nanotechnology. 2016. № 4. С. 10-20.
6. Островский О.Е., Круковский В.Н., Бук Б.Б. Влияние активирующих флюсов на проникающую способность сварочной дуги
и концентрацию энергии в анодном пятне // Сварочное производство. 1977. № 3. С. 3-4.
7. Савицкий М.М., Лесков Г.И. Механизм электроотрицательных элементов по свойству проникновения дуги с вольфрамовым катодом // Автоматическая сварка. 1980. № 9. С. 17-23.
8. Букаров В.А., Ищенко Ю.С., Ерохин А.А. Некоторые характеристики дуги при сварке стали 18-8 с окисленной поверхностью // Сварочное производство. 1975. № 10. С. 3-4.
9. Leconte S., Paillard P., Chapelle P., Henrion G., Saindrenan J. Effect of oxide fluxes on activation mechanisms of tungsten inert gas process // Science and Technology of Welding and Joining. 2006. Vol. 11. № 4. Pp. 389-397.
10. Симоник А.Г., Петвиашвили В.И., Иванов А.А. Эффект искривления при введении электроотрицательных элементов // Сварочное производство. 1976. № 3. С. 49-51.
11. Ishizaki K. et al. Interfacial Tension Theory on the Phenomena of Arc Welding // J. Japan Welding Society (JWS). 1965. Vol. 34. № 2. P. 146.
12. Mills K.C., Keene B.J., Brooks R.F., Shirali A. Marangoni effects in welding // Philos. Trans. R. Soc. Math. Phys. Eng. Sci. 1998. Bd. 356. № 1739. Pp. 911-925.
