scholarly journals EBSD Investigation of the Microtexture of Weld Metal and Base Metal in Laser Welded Al–Li Alloys

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2357 ◽  
Author(s):  
Li Cui ◽  
Zhibo Peng ◽  
Xiaokun Yuan ◽  
Dingyong He ◽  
Li Chen
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Transverse Section ◽  
Grain Morphology ◽  
Structural Features ◽  
Butt Joint ◽  
Horizontal Surface ◽  
Boundary Misorientation ◽  
Texture Intensity ◽  
Highly Correlated

Autogenous laser welding of 5A90 Al–Li alloy sheets in a butt-joint configuration was carried out in this study. The microstructure characteristics of the weld metal and base metal in the horizontal surface and the transverse section of the welded joints were examined quantitatively using electron back scattered diffraction (EBSD) technique. The results show that the weld metal in the horizontal surface and the transverse section exhibits similar grain structural features including the grain orientations, grain shapes, and grain sizes, whereas distinct differences in the texture intensity and misorientation distributions are observed. However, the base metal in the horizontal surface and the transverse section of the joints reveals the obvious different texture characteristics in terms of the grain orientation, grain morphology, predominate texture ingredients, distribution intensities of textures, and grain boundary misorientation distribution, resulting in the diversity of the microhardness in the base metal and the softening of the weld metal. However, the degree of the drop in the hardness of the weld metal is highly correlated to the microtexture developed in the base metal.

Mechanical Properties of Shielded Metal Arc Welded Low Carbon Steel: Effect of Butt Joint Type and Uncapping of Excess Weldment

2015 ◽  
Vol 1125 ◽  
pp. 195-199
Author(s):  
Toto Triantoro Budi Wardoyo ◽  
S. Izman ◽  
Safian Sharif ◽  
Hosta Ardhyananta ◽  
Denni Kurniawan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Carbon Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Low Carbon Steel ◽  
Butt Joint ◽  
Low Carbon ◽  
Shielded Metal Arc Welding

In this paper, Shielded Metal Arc Welding (SMAW) was performed on low carbon steel with three types of butt joint (i.e., square, single V, and double V) and uncapping of the weldment. The welding performance is measured based on the mechanical properties (i.e., strength and hardness). Grain size and microstructure of the weldments were also evaluated. The results show that all tested samples show similar tensile strength, which means there was no significant effect of the type of butt joint type or uncapping. The hardness of the weld metal was found to be slightly higher than that of heat affected zone and base metal, in which both showed similar hardness values. The grain size of the weld metal was also finer than that of heat affected zone and base metal. This trend in hardness and grain size on three regions of the welded sample was the same regardless of the butt joint type and whether the weldment was uncapped or not.

Effect of Butt Joint on Mechanical Properties of Welded Low Carbon Steel

2013 ◽  
Vol 845 ◽  
pp. 775-778 ◽  
Author(s):  
Toto Triantoro Budi Wardoyo ◽  
S. Izman ◽  
Denni Kurniawan
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Butt Joint ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Effect of variation of the connection (butt joint) in low carbon steel resistance welding (shielded metal arc welding, SMAW) performance is investigated in this paper. Three types of butt joint was varied: square, single V, and double V. The results from tensile test showed that welded specimens are of similar tensile properties with base metal and one another. When hardness test was performed on weld metal, HAZ, and base metal of each specimen,.it was found that weld metal and HAZ were of higher hardness than the base metal. Specimen with square joint exhibits the highest hardness while specimens with single V and double V joints show similar hardness. Microstructure analysis revealed that weld metal of specimen with square joint is of bainite-martensite phases while weld metal of specimens with single V and double V joints are of ferrite-pearlite phases. This difference in microstructure, and hence in hardness, is related to the corresponding heat input during welding.

NIMROD 617KS

Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Weld Metal ◽  
Tensile Properties ◽  
Base Metal ◽  
Heat Treating ◽  
Nominal Composition

Abstract Nimrod 617KS is an Inconel-type consumable with a nominal composition of nickel, 24% Cr,12% Co, and 9% Mo and is used to join UNS N06617 and Nicrofer 6023 to themselves. The alloy is designed for high-temperature service and is often used as the weld metal in dissimilar cases to ensure the weld is as strong as the base metal. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and joining. Filing Code: Ni-583. Producer or source: Metrode Products Ltd.

Effect of Chemical Composition of Welding Wire and Low Temperature Steel Plate on the Weld Properties Made by SAW

2008 ◽  
Vol 580-582 ◽  
pp. 57-60
Author(s):  
Hee Joon Sung ◽  
Yeon Baeg Goo ◽  
Kyeong Ju Kim ◽  
Kee Young Choi
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Weld Metal ◽  
Steel Plate ◽  
Butt Joint ◽  
Welding Wire ◽  
High Hardenability ◽  
Weld Metals ◽  
Weld Properties ◽  
Mo Content

Chemical composition effect on the weld properties for low temperature steel was evaluated. The alloy elements of interest at the weld metal were Cr and Mo, which come from the steel plate and welding wire, respectively. Both side one run SAW process was carried out in a Ygroove butt joint. Microstructure of the weld metal is strongly dependent on the chemical composition of the steel plate and the welding wire, due to high dilution. The microstructure of the weld metal became fine acicular ferrite by increasing Cr and Mo content because of high hardenability effect. The weld metal having Cr and Mo possessed the highest impact toughness at low temperatures among the weld metals studied. Cr seems to have more effect than Mo on the toughness of the weld metal.

scholarly journals Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

2021 ◽  
Vol 11 ◽  
Author(s):  
Codruţa Şoica ◽  
Mirela Voicu ◽  
Roxana Ghiulai ◽  
Cristina Dehelean ◽  
Roxana Racoviceanu ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Treatment Options ◽  
Active Role ◽  
Structural Features ◽  
Sex Hormone ◽  
Ongoing Research ◽  
New Treatment ◽  
Highly Correlated

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

scholarly journals Continuous Cooling Transformation Diagrams of 2.25Cr-1Mo-0.25V Submerged-Arc Weld Metal and Base Metal

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1055
Author(s):  
Hannah Schönmaier ◽  
Bernd Loder ◽  
Thomas Fischer ◽  
Fred Grimm ◽  
Ronny Krein ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weld Metal ◽  
Base Metal ◽  
Lower Bainite ◽  
Continuous Cooling Transformation ◽  
Continuous Cooling ◽  
Upper Bainite ◽  
Cct Diagrams ◽  
Scanning Electron

The transformation behavior and microstructural evolution during continuous cooling within the heat affected zone between the weld beads of a 2.25Cr-1Mo-0.25V all-weld metal and the corresponding 2.25Cr-1Mo-0.25V base metal were investigated by means of dilatometer measurements, optical and scanning electron microscopy. Furthermore, macro-hardness measurements were conducted and the ferrite phase fraction was analyzed from optical microscopic images using an imaging processing program. Thereupon a continuous cooling transformation (CCT) diagram for the 2.25Cr-1Mo-0.25V base metal and three welding CCT diagrams with different peak temperatures were constructed to realistically simulate the temperature profile of the different regions within the heat affected zones between the weld beads of the multi-layer weld metal. The microstructural constituents which were observed depending on the peak temperature and cooling parameters are low quantities of martensite, high quantities of bainite and in particular lower bainite, coalesced bainite and upper bainite as well as ferrite for the welding CCT diagrams. Regarding the base metal CCT diagram, all dilatometer specimens exhibited a fully bainitic microstructure consisting of lower bainite, coalesced bainite and upper bainite. Only the slowest cooling rate with a cooling parameter of 50 s caused a ferritic transformation. Nevertheless, it has to be emphasized that the distinction between martensite and bainite and the various kinds of bainite was only possible at higher magnification using scanning electron microscopy.

Investigation of Microstructure and Mechanical Properties of Semi-Solid State Joining of SSM Aluminum Alloys

2014 ◽  
Vol 496-500 ◽  
pp. 371-375 ◽  
Author(s):  
Apirit Petkhwan ◽  
Prapas Muangjunburee ◽  
Jessada Wannasin
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Weld Metal ◽  
Butt Joint ◽  
A356 Aluminum Alloy ◽  
Globular Microstructure ◽  
Microstructure And Mechanical Properties ◽  
A356 Aluminum ◽  
Semi Solid ◽  
Solid State Joining

In this research, the semi-solid state joining of SSM A356 aluminum alloy was investigated. The butt-joint of SSM A356 was heated by an induction heating coil to create a localized semisolid pool. Then a stirrer was applied into the joint seam in order to mix the weld metal. The accurate controlling of temperature during joining was measured. The effects of stirring rate on physical, macrostructure, microstructure and mechanical properties were studied. Experimental results showed that increase in stirring rates, the surface of the joint was smooth. The weld metal consisted of the globular microstructure and also voids. The density of weld metal zone increased by an appropriate stirring. The best tensile strength was achieved with 1750 rpm, 70 mm/min for 103.4 MPa.

Investigation of the Beltline Welding Seam and Base Metal of the Greifswald WWER-440 Unit 1 Reactor Pressure Vessel

2009 ◽  
Author(s):  
Jan Schuhknecht ◽  
Hans-Werner Viehrig ◽  
Udo Rindelhardt
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Pressure Vessel ◽  
Master Curve ◽  
Reactor Pressure Vessel ◽  
Reference Temperature ◽  
Metal Ring ◽  
Welding Seam ◽  
Root Region ◽  
Reactor Pressure

The investigation of reactor pressure vessel (RPV) materials from decommissioned NPPs offers the unique opportunity to scrutinize the irradiation behaviour under real conditions. Material samples taken from the RPV wall enable a comprehensive material characterisation. The paper describes the investigation of trepans taken from the decommissioned WWER-440 first generation RPVs of the Greifswald NPP. Those RPVs represent different material conditions such as irradiated (I), irradiated and recovery annealed (IA) and irradiated, recovery annealed and re-irradiated (IAI). The working program is focussed on the characterisation of the RPV steels (base and weld metal) through the RPV wall. The key part of the testing is aimed at the determination of the reference temperature T0 following the ASTM Test Standard E1921-05 to determine the fracture toughness of the RPV steel in different thickness locations. In a first step the trepans taken from the RPV Greifswald Unit 1 containing the X-butt multilayer submerged welding seam and from base metal ring 0.3.1 both located in the beltline region were investigated. Unit 1 represents the IAI condition. It is shown that the Master Curve approach as adopted in ASTM E1921 is applicable to the investigated original WWER-440 weld metal. The evaluated T0 varies through the thickness of the welding seam. The lowest T0 value was measured in the root region of the welding seam representing a uniform fine grain ferritic structure. Beyond the welding root T0 shows a wavelike behaviour. The highest T0 of the weld seam was not measured at the inner wall surface. This is important for the assessment of ductile-to-brittle temperatures measured on sub size Charpy specimens made of weld metal compact samples removed from the inner RPV wall. Our findings imply that these samples do not represent the most conservative condition. Nevertheless, the Charpy transition temperature TT41J estimated with results of sub size specimens after the recovery annealing was confirmed by the testing of standard Charpy V-notch specimens. The evaluated Charpy-V TT41J shows a better accordance with the irradiation fluence along the wall thickness than the Master Curve reference temperature T0. The evaluated T0 from the trepan of base metal ring 0.3.1 varies through the thickness of the RPV wall. T0 increases from −120°C at the inner surface to −104°C at a distance of 33 mm from it and again to −115°C at the outer RPV wall. The KJc values generally follow the course of the MC, although the scatter is large. The re-embrittlement during 2 campaigns operation can be assumed to be low for the weld and base metal.

scholarly journals A Combination of Keyhole GTAW with a Trapezoidal Interlayer: A New Insight into Armour Steel Welding

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3571 ◽  
Author(s):  
Zhenyu Fei ◽  
Zengxi Pan ◽  
Dominic Cuiuri ◽  
Huijun Li ◽  
Azdiar A. Gazder
Keyword(s):  
Chemical Composition ◽  
Weld Metal ◽  
Base Metal ◽  
Welding Process ◽  
Charpy Impact ◽  
Filler Materials ◽  
Temperature Phase ◽  
Ballistic Performance ◽  
Two Phase ◽  
Armour Steel

The ballistic performance of armour steel welds using austenitic filler materials is poor on account of the disparity in the mechanical properties of the weld and base metals. Consequently, a novel Keyhole Gas Tungsten Arc Welding process with a trapezoidal AISI309 austenitic stainless steel interlayer was developed to tailor chemical composition and microstructure by controlling the solidification sequence. Results show that the dilution rate in the weld metal region can reach up to 43.5% by placing a specially designed interlayer in between the base metal, providing a major scope for microstructure modification. Detailed weld analysis was undertaken by X-ray diffraction, optical and secondary and transmission electron microscopy, energy dispersive spectroscopy and electron back-scattering diffraction. The results from Vickers hardness indents and Charpy impact toughness testing at −40 °C show that the properties of the weld metal region are comparable to that of the base metal. This is ascribed to the weld metal comprising a two phase microstructure of martensite and retained austenite, which contribute to improvements in strength and toughness, respectively. Furthermore, the tailored chemical composition, microstructure and low temperature phase transformation in the weld metal may reduce the tendency toward both solidification cracking and hydrogen assisted cold cracking.

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