scholarly journals The Analysis of the Post-Operation Microstructure and Mechanical Properties of the Similar Welded Joint

2020 ◽  
pp. 37-41
Author(s):  
Agata Merda ◽  
Klaudia Klimaszewska
Keyword(s):  
Mechanical Properties ◽  
Welded Joint ◽  
Base Material ◽  
Steam Pressure ◽  
Test Material ◽  
Quality Level ◽  
Fine Grained ◽  
Post Operation ◽  
Non Destructive ◽  
M23c6 Carbides

The test material was a specimen sampled from sections of a pipe operated for 41,914 hours at a temperature of 575°C and under a steam pressure of 28.2 MPa. The specimen subjected to metallurgical tests was a welded joint made of austenitic steel TP347HFG. The non-destructive tests and the macroscopic tests confirmed the lack of any welding imperfections. The test joint represented quality level B in accordance with related standard requirements. The microstructural tests of the heat-affected zone (HAZ) revealed the presence of the fine-grained austenitic structure with numerous precipitates on grain boundaries – probably M23C6 carbides. In spite of long-lasting operation, the mechanical properties of the test welded joint were high and did not exceed the standard-related requirements concerning the base material.

Yb:YAG Disc Laser Welding of Austenitic Stainless Steel Without Filler Material

2009 ◽  
Vol 410-411 ◽  
pp. 87-96 ◽  
Author(s):  
Markku Keskitalo ◽  
Kari Mäntyjärvi
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cross Sections ◽  
Base Material ◽  
Tensile Tests ◽  
Solidification Cracking ◽  
Filler Material ◽  
Test Material ◽  
Butt Weld

The laser weldability of austenitic stainless steel (ASS) is good because of the material’s high absorptivity and favourable microstructure. There can be a slight possibility of solidification cracking at high welding speeds and low Crekv/Niekv ratios. Test welds were welded with a Yb:YAG disc laser. The test material was 3.2 mm EN 1.4404 2H C700 type stainless steel plate which was work hardened by cold rolling. The test materials were welded with different heat inputs ranging from 0.024 kJ/mm to 0.12 kJ/mm and with 300 mm and 200 mm focal lengths. The weld seams were square-groove welded as butt weld without filler material. The edges of the groove were made by mechanical or laser cutting. The hardness profiles from cross-sections of the welds were measured with a Vickers microhardness tester using 200 g weight. The mechanical properties were tested with tensile tests. The welds were classified with radiographic verification by an accredited laboratory. A number of the welds were fatigue tested with a bending fatigue tester. The mechanical properties (Rp 0.2%, Rm) of the laser welds were almost the same as in the base material except at the highest heat input. In the radiographic classification, the welds which were welded to the laser-cut edge were classified as class B (accepted). The other welds were classified as class D or C (rejected). The main reasons for the rejection of welds made on mechanically cut edges were lack of penetration or undercut of the weld. A problem with mechanically cut edges, and hence the welds, is that they can be non-square and bent edge. Fatigue tests and tensile tests gave no evidence of solidification cracking in the microstructure of the solidified parts of the welds.

Mechanical Properties and Fracture Toughness of Aluminum Vessels by Friction Stir Welding

2004 ◽  
Author(s):  
Masahito Mochizuki ◽  
Masao Toyoda ◽  
Masayuki Inuzuka ◽  
Hidehito Nishida
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Crack Initiation ◽  
Base Metal ◽  
Welded Joint ◽  
Stir Zone ◽  
Crack Initiation And Propagation ◽  
Friction Stir ◽  
Fine Grained ◽  
Initiation And Propagation

Mechanical properties and fracture toughness in friction stir welded joint of vessels of structural aluminum alloy type A5083-O are investigated. Welded joint from 25 mm-thick plate is fabricated by one-side one-pass friction stir. Charpy impact energy and critical crack-tip opening displacement (CTOD) in friction stir weld are much higher than those of base metal or heat-affected zone, whereas mechanical properties such as stress-strain curve and Vickers hardness do not have a conspicuous difference. Effects of microstructure on crack initiation and propagation are studied in order to clarify the difference of fracture toughness between stir zone and base metal. Both tensile test and bending test show that the fine-grained microstructure in stir zone induces to increase ductile crack initiation and propagation resistance by analyzing fracture resistance curves and diameter of dimples in fracture surface. It is found that high fracture toughness value in stir zone is affected fine-grained microstructure by friction stirring.

Mechanical Properties of Forged Ti-6Al-4V Structure by Electron Beam Welding

2012 ◽  
Vol 455-456 ◽  
pp. 308-313
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Shao Lin Li ◽  
Xiao Guang Yang
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Fusion Zone ◽  
Electron Beam Welding ◽  
Welded Joint ◽  
Base Material ◽  
Structure Design ◽  
Large Gradient ◽  
Welded Structure ◽  
Aero Engine

The blisk (bladed disk) is a new structural component of the modern aero-engine and plays an important role in improving its performance. Ti-6Al-4V alloy joints welded by electron beam have been widely used for compressor blisk in advanced aero engine. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded structure by electron beam welding (EBW) for failure analysis and structure design of blisk. Microstructure of Ti-6Al-4V welded structure by EBW was investigated by microscopic observation and micro indentation testing. Experiment results show grain coarsening in fusion zone (FZ) and heat affected zone (HAZ) appears large gradient organization structure, which presents significant local heterogeneity. On the centerline perpendicular to the welding direction, Vickers microhardness was measured in increments of 1mm, 0.5mm, 0.25mm and 0.1mm. Due to the presence of martensite, microhardness of the fusion zone is about 20% higher than that of the base material. The size of joints in different regions was acquired, 2.5 to 3.0-mm-wide in FZ and about 0.7-mm-wide in HAZ respectively. Three different types of EBW samples were designed for tensile test, including welded structure, welded joint and base material. Three different stress-strain curves of specimens were acquired, including welded joint. The experiment data indicates that the tensile strength of welded joints is 8% more than that of the base metal.

Microstructures and Properties of FSW Joints of AZ31B Mg Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 855-859 ◽  
Author(s):  
Si Rong Yu ◽  
Xian Jun Chen
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Base Material ◽  
Alloy Sheet ◽  
Weld Nugget ◽  
Mg Alloy ◽  
Material Strength ◽  
Nugget Zone ◽  
Friction Stir

The extruded AZ31B Mg alloy sheet was welded with friction stir welding. The microstructures and mechanical properties of the welded joint were investigated. The results show that the grains in the weld nugget zone were small, uniform and equiaxed. The grains in thermo-mechanical affected zone were stretched and relatively small, but were not as small and uniform as those in the weld nugget zone. The grains in the heat-affected zone were relatively coarse. The fracture of the welded joint occurred mainly in the heat affected zone. The tensile strength of the welded joints was up to 257.4 MPa and was 87.9% of the base material strength. The microhardness in the weld nugget zone was higher. The microhardness in the thermo-mechanical affected zone and heat affected zone were lower than that in the weld nugget zone. The microhardness in the weld nugget zone increased from the upper surface to the bottom.

scholarly journals DIAGNOSTICS OF THE PHYSICAL AND MECHANICAL PROPERTIES OF THE METAL BY THE PARAMETERS OF THE ELASTIC-PLASTIC INDENTATION OF A SPHERICAL INDENTER

2020 ◽  
pp. 58-62
Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Spherical Indenter ◽  
Test Material ◽  
Tensile Stresses ◽  
Elastic Plastic ◽  
Plastic Indentation ◽  
Non Destructive ◽  
Destructive Methods

The paper describes non-destructive methods for determining the physical and mechanical properties of metals based on the regularities of elastic-plastic indentation of a spherical indenter into the test material. Using the proposed methods makes it possible to construct a diagram of true tensile stresses based on the results of a single indentation of a spherical indenter.

Research on GTAW/SMAW Weldability of ADI/DI Using Electrodes ENi-Cl and ENiFe-Cl-A

2015 ◽  
Vol 1128 ◽  
pp. 242-253
Author(s):  
Ioan Catalin Mon ◽  
Mircea Horia Tierean ◽  
Adel Nofal
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Ductile Iron ◽  
Arc Welding ◽  
Filler Metal ◽  
Welded Joint ◽  
Base Material ◽  
Mechanical Tests ◽  
X Rays ◽  
Gtaw Process

The present research is dedicated to weldability of Austempered Ductile Iron (ADI) and Ductile Iron (DI) using Shielded Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW) methods. The welds were done using the arc welding process with Nickel base filler materials: ENi-Cl and ENiFe-Cl-A. Each weldment was examined visually, with X-rays and mechanical tests. After the mechanical tests, tensile test and impact properties of the welded joint are lower than mechanical properties of the ADI base material using ENiFe-Cl-A filler metal and GTAW process. This type of filler metal ENiFe-Cl-A can be applied successfully only for repair by welding of ADI parts. Using ENi-Cl filler metal with GTAW process applied to DI, the mechanical tests, tensile test and hardness of the welded joint are greater than mechanical properties of the DI base material. This procedure can be applied for welding. In case on DI welded using SMAW with ENi-Cl electrodes, the hardness of the welded joint is lower than the hardness of base material. This procedure can be applied only for repair by welding.

scholarly journals The Effect of Service on Microstructure and Mechanical Properties of HR3C Heat-Resistant Austenitic Stainless Steel

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1297 ◽  
Author(s):  
Grzegorz Golański ◽  
Adam Zieliński ◽  
Marek Sroka ◽  
Jacek Słania
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Elevated Temperature ◽  
Austenitic Stainless Steel ◽  
Strength Properties ◽  
Test Material ◽  
Creep Properties ◽  
Test Steel ◽  
M23c6 Carbides ◽  
Large Primary

The physical metallurgical tests were performed on the test samples made of HR3C steel, taken from a section of a pipeline in the as-received condition and after approximately 26,000 h of service at 550 °C. In the as-received condition, the test material had austenitic microstructure with numerous large primary Z-phase precipitates inside the grains. The service of the test steel mainly contributed to the precipitation processes inside the grains and at the grain boundaries. After service, the following precipitates were identified in the microstructure of the test steel: Z-phase (NbCrN) and M23C6 carbides. The Z-phase precipitates were observed inside the grains, whereas M23C6 carbides - at the boundaries where they formed the so-called continuous grid. The service of the test steel contributed to the growth of the strength properties, determined both at room and elevated temperature (550, 600 °C), compared to the as-received condition. Moreover, the creep properties of HR3C steel after service were higher than those of the material in the as-received condition. The increase in the strength properties and creep resistance was connected with the growth of strengthening of the test steel by the precipitation of Z-phase and M23C6 carbides.

scholarly journals Analysis of Welded Joint Properties on an AISI316L Stainless Steel Tube Manufactured by SLM Technology

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4362 ◽  
Author(s):  
Petr Mohyla ◽  
Jiri Hajnys ◽  
Kristýna Sternadelová ◽  
Lucie Krejčí ◽  
Marek Pagáč ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Welded Joint ◽  
Base Material ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
3D Print ◽  
Material Defects ◽  
Joint Properties ◽  
Non Destructive ◽  
Positive Effect

This work is focused on the analysis of the influence of welding on the properties and microstructure of the AISI316L stainless steel tube produced by 3D printing, specifically the SLM (Selective Laser Melting) method. Both non-destructive and destructive tests, including metallographic and fractographic analyses, were performed within the experiment. Microstructure analysis shows that the initial texture of the 3D print disappears toward the fuse boundary. It is evident that high temperature during welding has a positive effect on microstructure. Material failure occurred in the base material near the heat affected zone (HAZ). The results obtained show the fundamental influence of SLM technology in terms of material defects, on the properties of welded joints.

scholarly journals Effect of TIG and FSW Welding Processes on Mechanical Properties of Al-4.2Mg-0.6Mn-0.4Sc-0.1Zr Alloy

2021 ◽  
Vol 71 (2) ◽  
pp. 299-304
Author(s):  
Srinivasa Rao Mallipudi ◽  
Tangudu Sai Shankar ◽  
Perumalla Srikar ◽  
Uppda Bhanoji Rao ◽  
Yandra Chandrasekhar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Bending Strength ◽  
Welded Joint ◽  
Testing Machine ◽  
Base Material ◽  
Material Strength ◽  
Test Machine ◽  
Friction Stir ◽  
Welding Processes

Abstract In this study, friction stir welding (FSW) and Tungsten gas welding (TIG) processes were used to weld 5 mm thick Al-4.2Mg-0.6Mn-0.4Sc-0.1Zr alloy plates. The FSwelds and TIG welds were tested for mechanical properties (hardness, ultimate tensile strength, bending strength and impact strength) by means of vicker’s hardness machine, universal testing machine and impact test machine respectively. The strength of the base material was higher, compared to the strength of the FSW and TIG welded joints. The strength of the TIG welded joint decreased, compared to the strength of the FSW welded joint. The microstructure features were also observed for base material with the aid of metallurgical microscope and compared the same with the microstructures of FSW and TIG welded joints. FSW change the material strength due to fine-grain refinement in the stir zone in Al-4.2Mg-0.6Mn-0.4Sc-0.1Zr alloy and therefore FS welded joint exhibited 91.6% joint efficiency followed by the TIG welded joint of 69.8%.

Sign in / Sign up

Export Citation Format

Share Document