Influence Of Non-Metallic Inclusions In Pipe Steels Of Strength Class X65-X80 On Values Of Impact Toughness Of Flash-Butt Welded Joints

AbstractNowadays, ultra-high hard armor (UHA) steels are employed in armor tracked vehicle (ATV) construction because of their high hardness, high strength to weight ratio, and excellent toughness. UHA steels are usually welded using austenitic stainless steel (ASS) welding consumables, to avoid hydrogen-induced cracking (HIC). The use of ASS consumables to weld the above steel was the only available remedy because of higher solubility of hydrogen in the austenitic phase. In this investigation, an attempt was made to investigate the effect of ASS consumables (with different Creq/Nieq ratio) on solidification mode, impact toughness and microstructural characteristics of shielded metal arc (SMA) welded UHA steel joints. The welded joints were characterised based on impact toughness properties, hardness, and microstructural features. As the ferrite number increases with an increase in Creq/Nieq ratio result in different solidification mode (A, FA, F). It is also found that ferrite number of weld metal has appreciable influence on impact toughness and has inversely proportional relationship with impact toughness of the welded joints.

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Influence of martensite-austenite (MA) on impact toughness of X80 line pipe steels

Materials Science and Engineering A ◽

10.1016/j.msea.2016.03.095 ◽

2016 ◽

Vol 662 ◽

pp. 481-491 ◽

Cited By ~ 49

Author(s):

Nazmul Huda ◽

Abdelbaset R.H. Midawi ◽

James Gianetto ◽

Robert Lazor ◽

Adrian P. Gerlich

Keyword(s):

Impact Toughness ◽

Pipe Steels ◽

Line Pipe

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Experience of Using Complex Modifiers to Increase Corrosion Resistance of Pipe Steels

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.316.369 ◽

2021 ◽

Vol 316 ◽

pp. 369-374

Author(s):

Aleksey N. Shapovalov ◽

Roman R. Dema ◽

Sergey P. Nefed'ev

Keyword(s):

Corrosion Resistance ◽

Rare Earth Metals ◽

Test Results ◽

Pipe Steels ◽

Low Oxygen ◽

Thermal Expansion Coefficients ◽

Barium Strontium ◽

Metallic Inclusions ◽

Expansion Coefficients ◽

Increase Corrosion Resistance

The article presents the test results of complex microcrystalline modifiers containing calcium, barium, strontium, rare earth metals. Complex modifiers were used in the processing of steel for 17G1S-U pipes in order to reduce its contamination with non-metallic inclusions, including corrosive ones. The use of modifiers allowed to reduce metal contamination by non-metallic inclusions of all kinds. The most experimental non-metallic inclusions were obtained during metal processing with INSTEEL®5.1 and INSTEEL®9.4 modifiers. In addition, the use of experienced modifiers ensured the production of complex oxysulfides of calcium, cerium and lanthanum with low oxygen content and thermal expansion coefficients, which increases the corrosion resistance of steel.

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Effects of Welding Processes on the Low Temperature Impact Toughness of Structural Steel Welded Joints

Journal of Korean Society of Steel Construction ◽

10.7781/kjoss.2012.24.6.693 ◽

2012 ◽

Vol 24 (6) ◽

pp. 693-700

Author(s):

Chin Hyung Lee ◽

Hyun Seop Shin ◽

Ki Tae Park

Keyword(s):

Low Temperature ◽

Impact Toughness ◽

Structural Steel ◽

Welded Joints ◽

Temperature Impact ◽

Low Temperature Impact Toughness ◽

Welding Processes

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State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.814.7 ◽

2013 ◽

Vol 814 ◽

pp. 7-18 ◽

Cited By ~ 2

Author(s):

Miodrag Arsić ◽

Zoran Odanovic ◽

Srdjan M. Bošnjak ◽

Mladen Mladenović ◽

Zoran Savić

Keyword(s):

Welded Joints ◽

Transverse Direction ◽

Magnetic Particle ◽

Guide Vane ◽

Base Material ◽

Metallic Inclusions ◽

Crack Type ◽

Turbine Runner ◽

Lamellar Tearing ◽

Non Destructive

During the refurbishment of the hydroelectric generating set A6 on HPP Djerdap 1, for the state analysis and assessment of the level and causes of degradation of the structure of the vertical Kaplan turbine runner guide vane apparatus non-destructive tests and inspections, as well as destructive tests of base material and welded joints, have been carried out after 40 years of service. Results of non-destructive tests performed on welded joints are presented in this paper (magnetic particle and ultrasonic inspection), as well as results of destructive tests of the base material and welded joints (testing of tensile properties, impact testing, metallographic analyses of the structure). A large number of crack type line indications were detected by magnetic particle inspections, while the occurrence of partial penetration in roots of welded joints was detected by ultrasonic inspections, as well as lamellar tearing of the base material. Tensile properties of tested samples taken in longitudinal and transverse direction fulfilled the requirements of the standard with certain deviations, which does not stand for samples taken in z-direction with significantly lower values of contraction of the cross-section than minimum prescribed values, which proves that base material is not resistant to the occurrence of lamellar cracks. Metallographic tests performed on specimens taken from the base material in longitudinal and transverse direction showed that the microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide, sulphide, silicate and aluminate type, while metallographic tests performed on specimens taken from welded joints showed that their microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide type. A large number of micro-and macro-cracks were detected in the microstructure as well. Experimental tests enabled the determination of the causes of occurrence of lamellar tearing in base material and crack type defects in welded joints, while analytical calculation that refers to the stress state enabled integrity of welded structure of the upper ring of the turbine runner guide vane apparatus.

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EFFECT OF CeF3 ON NON-METALLIC INCLUSIONS AND IMPACT TOUGHNESS OF SELF-SHIELDEDLUX CORED WELD

Journal of Mechanical Engineering ◽

10.3901/jme.2005.01.221 ◽

2005 ◽

Vol 41 (01) ◽

pp. 221

Author(s):

Ping Yu

Keyword(s):

Impact Toughness ◽

Metallic Inclusions

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Austenite Decomposition Kinetics in Laser-Hybrid Welding of Steel of Strength Class K52

Materials Science Forum ◽

10.4028/www.scientific.net/msf.946.950 ◽

2019 ◽

Vol 946 ◽

pp. 950-955 ◽

Cited By ~ 1

Author(s):

A.I. Romantsov ◽

M.A. Fedorov ◽

D.G. Lodkov

Keyword(s):

Welded Joints ◽

Strength Class ◽

Defect Formation ◽

Welding Process ◽

Decomposition Kinetics ◽

Hybrid Welding ◽

Austenite Decomposition ◽

Laser Hybrid Welding ◽

Laser Hybrid ◽

The Impact

A modern technology for joining materials welding is commonly used in various industries. It is a process of interaction of thermal, mechanical and metallurgical properties and behaviors. Complex phenomena, such as solidification, microstructural changes and defect formation, have a great impact on the quality of welded joints. This article presents the results of studying the features of the austenite decomposition kinetics in the application of laser-hybrid welding technology, in a combination with multi-arc automatic submerged arc welding. The cooling rates are determined, affecting the change in properties of HAZ of welded joints on pipe steel of strength class K52. Using the dilatometric method, studies were conducted and thermo-kinetic and structural diagrams were constructed. Analysis of diagrams and microstructures showed that, as a result of the impact of the laser-hybrid welding process in the area of HAZ, the decomposition of austenite occurs mainly in the martensitic zone, followed by the formation of a bainite-perlite structure, due to recrystallization from the heat generated by the facing seams.

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