scholarly journals Strength of Materials at Elevated Temperatures. Creep Deformation Behavior of Weld Metal and Heat Affected Zone on 316FR Steel Thick Plate Welded Joint.

1999 ◽  
Vol 48 (2) ◽  
pp. 116-121 ◽  
Author(s):  
Hiromichi HONGO ◽  
Masayoshi YAMAZAKI ◽  
Takashi WATANABE ◽  
Junichi KINUGAWA ◽  
Tatsuhiko TANABE ◽  
...  
Keyword(s):  
Weld Metal ◽  
Creep Deformation ◽  
Heat Affected Zone ◽  
Deformation Behavior ◽  
Thick Plate ◽  
Elevated Temperatures ◽  
Welded Joint ◽  
Strength Of Materials

scholarly journals Strength of Materials at Elevated Temperatures. Long Term Creep-Rupture Properties and Microstructure of Weld Metal on 2.25Cr-1Mo Steel Thick Plate.

1999 ◽  
Vol 48 (2) ◽  
pp. 122-129 ◽  
Author(s):  
Takashi WATANABE ◽  
Masayoshi YAMAZAKI ◽  
Hiromichi HONGO ◽  
Junichi KINUGAWA ◽  
Tatsuhiko TANABE ◽  
...  
Keyword(s):  
Weld Metal ◽  
Thick Plate ◽  
Elevated Temperatures ◽  
Creep Rupture ◽  
Strength Of Materials ◽  
Term Creep ◽  
Rupture Properties

scholarly journals Effect of Local Fluctuation of the High Temperature Strength Properties in Weld Metal on Creep Deformation Behavior of Multi-Layer Welded Joint

2005 ◽  
Vol 54 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Hiromichi HONGO ◽  
Masayoshi YAMAZAKI ◽  
Takashi WATANABE ◽  
Masaaki TABUCHI ◽  
Tatsuhiko TANABE ◽  
...  
Keyword(s):  
High Temperature ◽  
Weld Metal ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Welded Joint ◽  
Strength Properties ◽  
High Temperature Strength

Region-Specified Ratcheting Behavior of API X80 Welded Joint Under Uniaxial Cyclic Loading

2016 ◽  
Author(s):  
Hongsheng Lu ◽  
Yonghe Yang ◽  
Gang Chen ◽  
Xu Chen ◽  
Xin Wang
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Pipeline Steel ◽  
Coarse Grained ◽  
Strain Accumulation ◽  
Lower Strength ◽  
Fine Grained ◽  
Ratcheting Strain

Evaluation of mechanical performance of different regions can be difficult by using standard size samples due to the size limitation of weld metal and heat-affected zone (HAZ). At first, the microstructure of different regions was characterized and quantified by Scanning Electron Microscope, which indicate that the pipeline steel is a typical acicular ferrite steel. In this study the deformation behavior of different regions (base metal, weld metal and heat affected zone) in a welded joint of API X80 pipeline steel were studied by conducting uniaxial loading tests on miniature specimens with the cross section of 2×0.5mm and gauge length of 9mm. From the results of uniaxial tension in base metal and weld metal it is shown that the welding is overmatching. Compared to the base metal, the coarse grained HAZ exhibits a lower strength, while the fine grained HAZ exhibits a higher strength. Under near zero-to-tension cyclic stress loading, all regions of the welded joints exhibit progressive accumulation of plastic strain. Under the same stress level, the base metal shows the fastest ratcheting strain accumulation, which is the result of lower strength than other regions. This fact may indicate that the ratcheting behavior of the overall welded joint is highly dependence on that of base metal for the present case. But when under the same normalized stress level (σ = σ/σYS), the fine grained HAZ has the highest ratcheting strain accumulation, while the coarse grained HAZ has the lowest ratcheting strain accumulation, which reveals that the intrinsic resistance to ratcheting is yield strength dependent.

Effect of structure on operational properties of welded joint made of heat-temperature alloy Fe—25Cr—35Ni

2020 ◽  
pp. 551-562
Author(s):  
M.A. Frolov ◽  
M.D. Fuks ◽  
S.Yu. Kondrat'ev
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Alloy Structure ◽  
Heat Temperature ◽  
Austenitic Alloy ◽  
X Ray ◽  
Effect Of Structure

The structure and mechanical properties of pipe welded joint made of heat-resistant austenitic alloy based on the Fe —25Cr—35Ni system are studied by optical and electron microscopy and X-ray spectral microanalysis. Signifi cant structural inhomogeneity in various zones of the welded joint and the formation of intermetallic G-phase in the heat-affected zone and weld metal are revealed. It is shown that the changing in the alloy structure during welding leads to signifi cant decrease in the mechanical properties of the welded joint.

Welding of differentially heat-strengthened rails. Laboratory studies

2020 ◽  
Vol 63 (7) ◽  
pp. 504-511
Author(s):  
N. A. Kozyrev ◽  
R. A. Shevchenko ◽  
A. A. Usol’tsev ◽  
A. N. Prudnikov
Keyword(s):  
Weld Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Welded Joint ◽  
Volume Fraction ◽  
Rail Steel ◽  
Isothermal Holding ◽  
Thermal Imager ◽  
Butt Welding ◽  
Contraction Ratio

In laboratory conditions, influence of modes of welding with subsequent isothermal holding on quality parameters of welded joint was studied on rail steel samples. Samples were welded with pulses of alternating electric current after welding. Welding was carried out on MS-2008M resistance butt welding machine with a number of alterations of control actions. To measure temperature of the metal in heat affected zone (HAZ), chromel-alumel thermocouples were used. Collection and processing of data from thermocouples was carried out using TEMPOL measuring complex. Temperature of the weld (where it is not possible to install a thermocouple) was measured using HotFind-D thermal imager. Experimental results and physicomechanical properties of the samples are presented: HB hardness, HAZ length, yield strength, tensile strength, ultimate elongation, contraction ratio, and presence of non-metallic inclusions in weld metal. Deviations of hardness were calculated in comparison with the requirements established by GOST R 51685 – 2013 state standard on the surface of samples’ welded joints: decrease-increase and total deviation of hardness. Method of resistant butt welding is proposed, which makes it possible to obtain welded joint of items produced of rail steel with a uniform distribution of hardness and small zone of thermal influence. Dependence of microhardness on volume fraction of structural components was determined. Models of impact of pulsed contact post-welding heating parameters on lowering hardness of weld metal compared to the base metal and on the extent of heat-affected zone were constructed. The proposed method allows us to adjust structure of metal welded joints of rails without additional local heat treatment.

Effect of the Hydrostatic Pressure in the Diffusible Hydrogen at the Underwater Wet Welding

2012 ◽  
Author(s):  
Weslley Carlos Dias da Silva ◽  
Leandro Fonseca Ribeiro ◽  
Alexandre Queiroz Bracarense ◽  
Ezequiel Caires Pereira Pessoa
Keyword(s):  
Hydrostatic Pressure ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Diffusible Hydrogen ◽  
Chromatography Method ◽  
Underwater Wet Welding ◽  
Residual Tension ◽  
Residual Hydrogen ◽  
Welding Pressure

The underwater wet welding using SMAW is widely used in maintenance and repairs of submerged structures. In this process, water can dissociate, providing substantial quantities of ions H+ and O2− at the molten pool. Hydrogen and oxygen may constitute gas bubbles in the molten weld metal which may result in formation of pores. The hydrogen can diffuse by the weld metal and heat-affected zone or be trapped in the structure of the weld metal in the form of residual hydrogen. The diffusible hydrogen in the weld metal and heat-affected zone might have a deleterious effect in the mechanical properties of welded joint. The diffusible hydrogen plus susceptible microstructure, such as martensite, presence of tensile residual tension and temperatures lower than 200°C can lead the arising of cracks in the weld metal and heat-affected zone. All these conditions are satisfied in underwater wet welding. The amount of diffusible hydrogen in the weld metal can be influenced by several factors. However, it is not yet known whether the depth of welding (pressure) affects the amount of diffusible hydrogen in weld metal. In this work, several measurements of diffusible hydrogen were made at following depth: 0.30m, 10m, 20m and 30m at wet welding. The electrode used was commercial waterproofed E6013. The diffusible hydrogen measurements were made through the gas chromatography method following the AWS D3.6M procedure. The porosity was measured using the macrographic method and a software called Quantikov. The weld bead reinforcement and width were also measured. The residual hydrogen also was measured. The results showed that diffusible hydrogen reduced substantially as the hydrostatic pressure increased. The porosity, as it was related previously, increased as the hydrostatic pressure increased. Changes in the residual hydrogen of the weld metal were not observed. So, it was possible to conclude that the welding depth affects directly the diffusible hydrogen and porosity levels of underwater wet welds.

Effect of Simulated Heat Affected Zone Thermal Cycle on the Creep Deformation and Damage Response of Grade 91 Steel Including Heat-to-Heat Variation

2018 ◽  
Author(s):  
Yukio Takahashi ◽  
Haruhisa Shigeyama ◽  
John Siefert ◽  
Jonathan Parker
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Creep Strength ◽  
Creep Deformation ◽  
Heat Affected Zone ◽  
Thermal Cycle ◽  
Power Plants ◽  
Temperature History ◽  
Wide Range ◽  
Grade 91

Grade 91 and other creep strength enhanced ferritic steels are widely used in fossil power plants as the structural materials of high temperature piping and components. As the operating temperature of these plants is as high as 600°C, creep deformation and accompanying damage cannot be neglected in evaluating their integrity. In particular, creep damage tends to concentrate in the softened heat-affected zone in welded joints and often caused so-called type-IV cracking, in advance of failure in base metal or weld metal. In evaluating the likelihood of such a failure, it is important to understand the mechanical property of such region in comparison with base metal and weld metal. Previous studies have shown that considerable degradation of creep strength brought by thermal cycles simulating the temperature history experienced by such a zone. In order to strengthen the understanding, thermal cycle was given to six Grade 91 heats encompassing a wide range of creep properties and their creep behavior was evaluated in this study. As a result, it was found that resistance for creep deformation and rupture life of six heats showed different trend than what was observed in the original metal but the heat-dependency of the ductility seems to be inherited.

Effect of Weld Metal Hardening Property on Deformation Behavior and Crack Driving Force of Mismatched Welded Joint

2011 ◽  
Vol 314-316 ◽  
pp. 2429-2432
Author(s):  
Lin Yu Xiong ◽  
Yan Hua Zhang
Keyword(s):  
Weld Metal ◽  
Deformation Behavior ◽  
Driving Force ◽  
Welded Joint ◽  
Crack Tip ◽  
Local Deformation ◽  
Small Scale ◽  
Crack Driving Force ◽  
Deformation Level ◽  
Metal Hardening

Effect of weld metal hardening property on the deformation behavior and crack driving force of strength mismatched welded joint with crack has been investigated using finite element method under plain strain condition. The results show that when the apply load is small, there is only small scale deformation around the crack tip, the whole structure is still in linear or small scale yielding condition therefore the weld metal hardening property has no significant effect on crack driving force. As the applied load increasing, the deformation region enlarges and at the same time the deformation level around the crack tip deepens, the increasing of weld metal hardening property decreases the local deformation level, consequently leading to the decreasing of the crack cracking force.

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