scholarly journals INFLUENCE OF THE CHEMICAL COMPOSITION AND METHOD OF SMELTING ON THE PROPERTIES OF THE METAL OF WELDED JOINTS OF ECONOMICALLY ALLOYED CHROMIUM-MANGANESE-NICKEL STEELS

2021 ◽  
pp. 69-73
Author(s):  
O. P. Bondareva ◽  
E. V. Sedov ◽  
O. B. Kryuchkov ◽  
I. L. Gonik
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Chemical Composition ◽  
Grain Growth ◽  
Base Metal ◽  
Welded Joints ◽  
Austenitic Steels ◽  
Welding Cycle ◽  
Thermal Welding ◽  
Positive Effect

The results of studies on the influence of the chemical composition on mechanical properties of the base metal and the metal of the near-seam zone of welded joints of ferrite-austenitic steels are presented. The positive effect of microalloying of steels with calcium and cerium on the resistance to embrittlement of the metal after exposure to the thermal welding cycle is shown. It is established that alloying ferrite-austenitic steels with molybdenum and vanadium reduces the tendency to grain growth during welding heating, and doping with nitrogen leads to the stabilization of the phase composition of steels under the influence of elevated welding and operating temperatures.

Influence of High-Calcium Ash Composition on the Composite Binders’ Properties

2021 ◽  
Vol 316 ◽  
pp. 1019-1024
Author(s):  
O. A. Ignatova ◽  
A. A. Dyatchina
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Cement Stone ◽  
Normal Density ◽  
Fine Aggregate ◽  
Equivalent Amount ◽  
High Calcium ◽  
Composition Structure ◽  
Kinetics Of ◽  
Positive Effect

The paper presents the studies’ results of chemical composition, structure, and physico-mechanical properties of high-calcium ashes from the Kansk-Achinsk coals (2017-2019 selection). It was found that ash has a complex poly-mineral composition and contains hydraulically active minerals and oxides of СаОfr, β-C2S, CA, C3A, C4AF, C2F, CaSO4. According to the content of CaOfr, MgO does not meet standards’ requirements. The uniformity of the volume change is maintained by the composition with 50% of cement. The structure and hardening kinetics of ash and ash-cement stone compositions, obtained from the test of normal density, were analyzed. It was established that the hardening of compositions with ash from the Kansk-Achinsk coals was largely influenced by ash minerals. An equivalent amount of cement in composite binders cannot be replaced. In order to obtain a positive effect, compositions with ash instead cement of no more than 30% and a part of fine aggregate, without exceeding the ratio of ash: cement = 1: 1, should be used.

Metallurgical and Mechanical Features of API 5L X65 Pipeline Steel Weldment

2002 ◽  
Author(s):  
Jang-Bog Ju ◽  
Jung-Suk Lee ◽  
Jae-Il Jang ◽  
Woo-Sik Kim ◽  
Dongil Kwon
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Welded Joints ◽  
Pipeline Steel ◽  
Steel Structures ◽  
Welding Residual Stress ◽  
Engineering Structures ◽  
Steel Weldment ◽  
Mechanical Factors ◽  
Fracture Performance

Substantial differences amongst metallurgical and mechanical properties of base metal (BM), weld metal (WM) and heat-affected zone (HAZ) occur in general in welded steel structures It is common practice in various engineering structures to evaluate the fracture performance of welded structures by mechanical testing. Especially, the HAZ of steel welded joints shows a gradient of microstructure and mechanical properties from the fusion line to the unaffected base metal. This study is concerned with the effects of metallurgical and mechanical factors on the fracture performance of API 5L X65 pipeline steel weldments, as they are generally used for main natural gas transmission pipelines in Korea. First of all, we investigated the microscopic and macroscopic fracture behavior of the various micro-zones within the HAZ from the viewpoint of metallurgical factors. The effects of mechanical factors such as welding residual stress in steel weldment and strength mismatch between BM and WM, particularly in high strength steel weldments, are also analyzed. Therefore, the fracture performance of API 5L X65 pipeline steel weldment was mainly dependent on the change of macrostructure and its distribution in the welded joints.

Tensile Strength of Forged Ti-6Al-4V Welded Joints by Electronic Beam Welding

2011 ◽  
Vol 255-260 ◽  
pp. 132-136
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Dong Pan ◽  
Shao Lin Li ◽  
Xiao Guang Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Welded Joints ◽  
Empirical Relationship ◽  
Weld Zone ◽  
Structure Design ◽  
Microstructure And Mechanical Properties ◽  
Welded Structure ◽  
Static Tensile

Forged Ti-6Al-4V welded structure by electronic beam welding (EBW) as integrally bladed disk (blisk) structure in advanced aero-engine has been widely applied. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded joints by EBW for failure analysis and structure design of blisk. Firstly the microstructure and mechanical properties of forged Ti-6Al-4V welded joints was focused on. Grains in the weld zone become coarse and large gradient organization structure appears in the heat affected zone (HAZ), which presents significant local heterogeneity. Microhardness of the weld zone is about 20% higher than that of the base metal. The size of different region of the welded joints was estimated. Then static tensile test of three different specimens were carried on. Experiment results show that the tensile and yield strength of welded joints are not less than that of the base metal. Finally the empirical relationship between strength and hardness of Ti-6Al-4V alloy is established. Tensile strength of the weld zone and the base metal were estimated. Compared to experiment data, the deviation is 3.56%, 0.097% respectively.

Mechanical Properties of Welded Joints in Welding with Pulsed Arcs

2013 ◽  
Vol 379 ◽  
pp. 195-198 ◽  
Author(s):  
A.G. Krampit ◽  
N.Yu Krampit ◽  
M.A. Krampit
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Power Supply ◽  
Welded Joints ◽  
Arc Welding ◽  
Welded Joint ◽  
Pulsed Power ◽  
Pulsed Arc Welding ◽  
Pulsed Power Supply ◽  
Pulsed Arc

Research results of the weld chemical composition and mechanical properties at pulsed arc welding are discussed. It is established that the pulsed power supply favours mechanical properties of the welded joint.

scholarly journals Effect of Alloying Composition on Microstructure and Mechanical Properties of Ultranarrow Gap Welded Joints of U71Mn Rail Steel

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lian Gong ◽  
Hui Liu ◽  
Cheng Lv ◽  
Lijun Zhao
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Welded Joints ◽  
Alloy Composition ◽  
Rail Steel ◽  
Base Material ◽  
Average Hardness ◽  
Microstructure And Mechanical Properties ◽  
Fine Pearlite ◽  
The Impact

A new welding method, ultranarrow gap welding with constrained arc by flux band, is proposed to compensate for the low quality of rail thermite welded joints. This article presents the results of research on the microstructure and mechanical properties of ultranarrow gap welded joints of U71Mn rail steel made using three types of alloying composition content flux bands. Results indicated that the base metal metallographic microstructure consisted mainly of pearlitic, the HAZ was mainly composed of fine pearlite, and the microstructure of the welded bead was composed of acicular ferrite, while the weld grain size decreased as the alloy composition increased. The average hardness noticeably changed in weld metal as the alloy composition increased, and when the alloy composition reached 19%, the hardness was equivalent to the base material. The average hardness value of the HAZ (35.8 HRC) was higher than that of the base metal (24.8 HRC). The tensile strength increased, and the percentage elongation after fracture decreased with increasing alloying composition from 9% to 19%. The impact absorbing energies were decreased as the alloying composition increased. Consequently, all the mechanical properties of rail ultranarrow gap welding were higher than those of the standard requirements of the rail flash welding. And the optimal alloying composition of flux band was 19%.

The Effect of Stand - Off Distance on the Mechanical Properties of TIG Butt Joints of 316 Stainless Steel

2020 ◽  
Vol 833 ◽  
pp. 59-65
Author(s):  
Hala M. Gnedi ◽  
Khawla T. Snoussi ◽  
Abulmaali M. Taher ◽  
Thoria G. Sharef ◽  
Yousef Arebi
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Base Metal ◽  
Welded Joints ◽  
Hardness Test ◽  
Scanning Speed ◽  
Geometrical Parameters ◽  
Worst Case ◽  
316 Stainless Steel ◽  
Hardness Values

The objective of this study is to investigate and determine the effect of the stand-off distance (distance between the welded plates) on the mechanical properties of the Tungsten Inert Gas (TIG) welded joints. Butt TIG welding was performed for 316 stainless steel (SS) by using different pre welding stand-off distances with fixing the other parameters (thickness of welded plates, voltage, current, groove shape, and scanning speed). The influence of the stand-off distance parameter was examined by using tensile test, hardness test in the three different regions (base metal, heat effected zone, and molten zone), non-destructive testing (including visual inspection, liquid pentrant and X – ray) and microscopic examinations. Results show that the stand-off distance is one of the most important geometrical parameters of the Butt welded joints to end by good mechanical properties. It is found that the optimum stand-off distance was about 1 mm (shows the highest hardness results), but still there were some defects in some spots in the molten metal zone which caused a decrease in the hardness values in these locations. The 2 mm stand-off distance shows reasonable results, and the worst case was recorded for the 0 mm stand-off distance condition. Generally the hardness values of the heat affected zone in all conditions were the highest when compared to both metal welding zone and the base metal zone.

Mechanical properties of welded joints of the pressed aluminum-magnesium 1565Ch alloy at low and high temperatures

2019 ◽  
pp. 57-67
Author(s):  
S. A. Zykov ◽  
V. I. Pavlova ◽  
E. P. Osokin
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Low Temperature ◽  
Base Metal ◽  
Welded Joints ◽  
Arc Welding ◽  
Cryogenic Temperature ◽  
Actual Strength ◽  
Temperature Hardening ◽  
Consumable Electrodes

The paper studies structure and mechanical properties of welded joints of hot-pressed panels and profiles manufactured by JSC Arkonik SMZ from aluminum-magnesium 1565ch alloy at the temperature range of –165 to 150°C. It is established that the nature of changes in the properties of welded joints of pressed panels and profiles of 1565ch alloy made by manual argon-arc welding with non-consumable electrodes of ArDS with filler material SwAMg-61 at various test temperatures is similar to changes of welded joints of rolled sheets. When the test temperature is lowered, low-temperature hardening of the welded joints takes place – at a cryogenic temperature (–165°C), 20–30% of strength is gained comparing to 20°C. The prolonged aging of welded joints at an elevated temperature (150°C) leads to strength decrease by 25–30% compared to that of 20°C. The coefficient of strength of welded joints with reinforced joint is not less than 0.9 of the actual strength of the base metal at all test temperatures.

Formation of structural parameters and mechanical properties of multi-element coatings based on niobium nitride under different deposition conditions

2021 ◽  
pp. 67-72
Author(s):  
V.P. Tabakov ◽  
A.V. Chikhranov ◽  
Ya.A. Dolzhenko
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Chemical Composition ◽  
Deposition Temperature ◽  
Chemical Elements ◽  
Structural Parameters ◽  
Niobium Nitride ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Deposition Conditions

The results of the dependence of the chemical composition of coatings based on niobium nitride on the layout of the installation are presented. The effect of the chemical elements content in coatings based on niobium nitride on the phase composition, structural parameters and mechanical properties is determined. The effect of the deposition temperature of coatings on the mechanical properties of wear-resistant coatings is studied.

scholarly journals Structure and Mechanical Properties of Explosive Welded Mg/Al Bimetal/ Struktura I Właściwości Mechaniczne Połączenia Uzyskanego Metodą Zgrzewania Wybuchowego Bimetalu Mg/Al

2014 ◽  
Vol 59 (4) ◽  
pp. 1593-1597 ◽  
Author(s):  
D. Balga ◽  
D. Ostroushko ◽  
K. Saksl ◽  
E. Mazancová ◽  
O. Milković
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Phase Composition ◽  
Chemical Composition ◽  
Phase Transformations ◽  
Explosion Welding ◽  
Lattice Parameters ◽  
Diffraction Experiment ◽  
X Ray ◽  
Cubic Phases

Abstract In the article we analyzed shape, local mechanical properties, chemical and phase composition of Magnesium/Aluminium cladded material prepared by explosion welding. In particular we focus our investigation on Mg/Al interface and areas close to the joint. Hardness of the joined materials measured far from their interface is similar for both materials, however in the region of interface the hardness drops down by 40%. Phase transformations in the interface was examined by a hard X-ray micro-diffraction experiment performed at beamline P07 at PETRA III at the energy of 99 keV which helped us identify in Al: fcc-Al, Al2Cu tetragonal and Al7Cu2Fe tetragonal and in Mg: hcp-Mg, Mg2Si cubic phases. In the interface we haven’t observed any new intermetallics, but computation of lattice parameters and profiles of Al and Mg peaks proved an existence of solid solution with different gradient of chemical composition.

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