APPLICATION OF BARIUM-STRONTIUM CARBONATITE FOR PRODUCTION OF WELDING FLUXES BASED ON SILICOMANGANAZE PRODUCTION SLAG

The study results of introduction of barium-strontium carbonatite of various fractional composition into flux based on silicomanganese production slag are presented. The principal possibility of using their mixtures for depositing and welding of low-alloy steels is shown, while the use of barium-strontium carbonatite makes it possible to reduce contamination of weld metal with nonmetallic inclusions. In series of experiments in laboratory conditions, various compositions of welding fluxes were made and investigated. As components, barium-strontium modifier BSC produced by “NPK Metallotechnoprom” LC under TU 1717-001-75073896-2005 was used, wt. %: 13.0 – 19.0 % BaO; 3,5 – 7,5 % SrO; 17.5 – 25.5 % CaO; 19.8 – 29.8 % SiO2 ; 0.7 – 1.1 % MgO; 2.5 – 3.5 % K2O; 1.0 – 2.0 % Na2O; 1.5 – 6.5 % Fe2O3 ; 0 to 0.4 % MnO; 1.9 – 3.9 % of Al2O3 ; 0.7 – 1.1 % TiO2 ; 16.0 – 20.0 % CO2 as well as silicomanganese slag produced by JSC “EVRAZ – West-Siberian Metallurgical Combine”, wt. %: 6.91 – 9.62 % Al2O3 ; 22.85 – 31.70 % CaO; 46.46 – 48.16 % SiO2 ; 0.27 – 0.81 % FeO; 6.48 – 7.92 % MgO; 8.01 – 8.43 % MnO; 0.28 – 0.76 % F; 0.26 – 0.36 % Na2O; up to 0,62 % K2O; 0.15 – 0.17 % S; 0.01 % P. Basis of the flux is silicomanganese production slag, into which a flux additive was introduced. Flux additive was produced in two ways. The first one: by mixing barium-strontium modifier with liquid glass in a ratio of 75 and 35 %, respectively. The second variant is as follows: dust of strontium-barium modifier of fraction less than 0.2 mm was used as a flux additive. The technology of flux-additive manufacturing is described. Welding of rollers was carried out using ASAW-1250 welding tractor. Regimes of surfacing were worked out. The chemical compositions of fluxes, slag crusts, flux and weld metal were determined. Metallographic studies of metal were performed. The results of analysis for presence of nonmetallic inclusions in weld zone were carried out in accordance with GOST 1778 – 70. Studies indicate a decrease in contamination of weld metal by silicates that are not deformed and absence of brittle silicates.

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DIFFUSION OF HYDROGEN IN WELDED JOINTS OF STRUCTURAL STEELS

Proceedings of Southwest State University ◽

10.21869/2223-1560-2017-21-6-85-95 ◽

2017 ◽

Vol 21 (6) ◽

pp. 85-95 ◽

Cited By ~ 3

Author(s):

N. N. Sergeev ◽

A. N. Sergeev ◽

S. N. Kutepov ◽

A. E. Gvozdev ◽

E. V. Ageev

Keyword(s):

Diffusion Coefficient ◽

Weld Metal ◽

Heat Affected Zone ◽

Welded Joints ◽

Chemical Potential ◽

Weld Zone ◽

Base Material ◽

High Strength ◽

Low Alloy Steels ◽

Alloy Steels

High-strength low-alloy steels are widely used in the construction of welded metal structures. The main advantage of these steels is good combination of strength and toughness, and weldability. However, when welding high strength low alloy steels during cooling of the weld to a temperature below 150-100 °C there may be a risk of formation of bulk crystal structures defects in the weld zone - cold cracks. It was experimentally established that one of the factors contributing to the formation of cold cracks may be the occlusion of hydrogen in the atmosphere of arc plasma in the solidifying weld metal, from which diffusion hydrogen may diffuse to different areas of the weld after cooling. Hydrogen cracking typically has a tendency to slow down i.e. cracks can occur several days after the completion of welding process. As a rule, hydrogen induced cracking occurs either in the original steel in the heat-affected zone or in the weld metal, which is important, topical and long been researched by various scientific schools. Modern technologies of high strength low alloy steels processing have significantly improved the quality of the base material by reducing the amount of carbon and impurities, which has increased the stability of weld in the heat affected zone (HAZ) to hydrogen induced cold cracking. The paper presents modern approaches to the definition of diffusion coefficient of hydrogen in welded joints of high-strength low-alloy steels. Taking into account the temperature, the gradient of chemical potential and continuity conditions there has been considered the process of mass transfer of hydrogen under the influence of diffuse inhomogeneous mediums. It has been shown that the local effects of changing pressure and chemical potential are described using the equation of generalized potential of the diffusing substance. Our paper presents analytical expressions to determine the apparent diffusion coefficient of hydrogen in different local areas of a welded joint depending on temperature.

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UNIFLUX VCM 125

Alloy Digest ◽

10.31399/asm.ad.sa0340 ◽

1978 ◽

Vol 27 (1) ◽

Keyword(s):

Carbon Dioxide ◽

Fracture Toughness ◽

Weld Metal ◽

Heat Treating ◽

Carbon Steels ◽

Low Alloy Steels ◽

Electrode Wire ◽

Molybdenum Steel ◽

Alloy Steels ◽

Welding Electrode

Abstract UNIFLUX VCM 125 is a continuous flux-cored welding electrode (wire) that is used to deposit 1 1/4% chromium-1/2% molybdenum steel for which it was developed. Welding is protected by a shielding atmosphere of 100% carbon dioxide. This electrode also may be used to weld other low-alloy steels and carbon steels; however, the weld metal may differ somewhat from 1 1/4% chromium-1/2% molybdenum because of weld-metal dilution. When Uniflux VCM 125 is used to weld 1 1/4% chromium-1/2% molybdenum steel, it provides 95,000 psi tensile strength at 70 F and 24 foot-pounds Charpy V-notch impact at 40 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-340. Producer or source: Unicore Inc., United Nuclear Corporation.

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Approximate calculations of oxygen dissolved in weld metal in welding low-alloy steels

Welding International ◽

10.1080/09507118909446660 ◽

1989 ◽

Vol 3 (9) ◽

pp. 790-792 ◽

Cited By ~ 1

Author(s):

M M Borisenko

Keyword(s):

Weld Metal ◽

Low Alloy Steels ◽

Alloy Steels

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The Role of Nonmetallic Inclusions in Accelerating the Local Corrosion of Metal Products Made of Plain-Carbon and Low-Alloy Steels

Metallurgist ◽

10.1007/s11015-005-0065-3 ◽

2005 ◽

Vol 49 (3-4) ◽

pp. 124-130 ◽

Cited By ~ 2

Author(s):

I. G. Rodionova ◽

O. N. Baklanova ◽

G. A. Filippov ◽

I. I. Reformatskaya ◽

A. N. Podobaev ◽

...

Keyword(s):

Nonmetallic Inclusions ◽

Local Corrosion ◽

Low Alloy Steels ◽

Alloy Steels ◽

Metal Products

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UNIFLUX V100

Alloy Digest ◽

10.31399/asm.ad.sa0339 ◽

1977 ◽

Vol 26 (12) ◽

Keyword(s):

Weld Metal ◽

Heat Treating ◽

Carbon Steels ◽

Low Alloy Steels ◽

Steel Weld ◽

Electrode Wire ◽

Steel Weld Metal ◽

Molybdenum Steel ◽

Alloy Steels ◽

Welding Electrode

Abstract UNIFLUX V100 is a continuous flux-cored welding electrode (wire) that is used to deposit 1/2% molybdenum steel weld metal when used to weld 1/2% molybdenum steel for which it was developed. Welding is protected by a shielding atmosphere of 75% argon-25% carbon dioxide. This electrode is also used to weld other low-alloy steels and carbon steels; however, the weld metal may differ somewhat from 1/2% molybdenum because of weld-metal dilution. Uniflux V100 is used widely in shipbuilding to weld 1/2% molybdenum steel. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-339. Producer or source: Unicore Inc., United Nuclear Corporation.

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Experimental investigation of structural integrity behavior of High strength low alloy steel – Study of mechanical, microstructural and corrosion behavior of Submerged arc welding weldments

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408920958104 ◽

2020 ◽

pp. 095440892095810

Author(s):

Lochan Sharma ◽

Rahul Chhibber

Keyword(s):

Corrosion Resistance ◽

Impact Strength ◽

Weld Metal ◽

Base Metal ◽

Arc Welding ◽

Weld Zone ◽

Submerged Arc Welding ◽

Welding Fluxes ◽

Submerged Arc ◽

Metal Impact

The present study aims at investigating the effect of submerged arc welding fluxes for enhanced corrosion resistance of structural steel welds. By varying the basicity index of submerged arc welding fluxes the corrosion resistance and mechanical properties of weld metal such as tensile strength, impact strength, microhardness in submerged arc weldments were evaluated. The result shows that with the increase in bascity index tensile strength of weld specimen reduced while impact strength and microhardness value increased. Maximum microhardness (288 HV) was observed for flux 2 while base metal show minimum microhardness value (205 HV). Flux 5 gives maximum impact strength (94.17 J) as compared to the base metal (80 J). This is due to the reduced content of oxygen in weld metal which increases the weld metal impact toughness. Corrosion resistance of weld specimen increased as compared to the base metal. Ductile fracture mode and shear lip or tears were observed in the weld zone. Shear dimples and shear lips were more severe in base metal as well as weld metal impact specimens due to the rapid effect of external forces on the impact test. The banded microstructure of delta ferrite and austenite was observed in the base metal. Fine grains of ferrite and pearlite at the center and edges were present in the weld zone.

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