Effect of N2 Addition on Microstructure and Properties of SAF 2507 Duplex Stainless Steels GTAW Welded Joint

2012 ◽  
Vol 724 ◽  
pp. 127-130
Author(s):  
Dong Fang Du ◽  
Jie Liu ◽  
Guo Ping Li ◽  
Jin Ming Liu
Keyword(s):  
Weld Metal ◽  
Impact Energy ◽  
Welded Joint ◽  
Welding Process ◽  
Welding Parameters ◽  
Shielding Gas ◽  
Micro Hardness ◽  
Weld Metals ◽  
Welding Arc ◽  
The Impact

In this paper, SAF2507 duplex stainless steel (DSS) was welded by GTAW with ER2594 as filler wire, and Ar + N2 as shielding gas. The results show that, with increasing the content of N2 in the shielding gas, the amount of austenite in weld metal increase, the micro-hardness drops and impact energy increases; the use of Ar +2 ~ 3% N2 welding parameters, the microstructure and mechanical properties of welded joints are the best, the austenitic rates and impact energy of weld metals are 51%~53% and 75~88 J, respectively, and the welding process is easy to control; when the content of N2 reach 5%, the impact energy of weld metal decreases obviously and the welding arc is unstable.

The Behaviour of Nitrogen on the Welding Parameters of the Dissimilar Weld Joints between AISI 304 and AISI 316L Austenitic Stainless Steels Produced by Gas Tungsten Arc Welding

2012 ◽  
Vol 248 ◽  
pp. 395-401 ◽  
Author(s):  
Wichan Chuaiphan ◽  
Loeshpahn Srijaroenpramong
Keyword(s):  
Weld Metal ◽  
Nitrogen Content ◽  
Welding Current ◽  
Welding Parameters ◽  
Aisi 316L ◽  
Arc Length ◽  
Aisi 304 ◽  
Dissimilar Weld ◽  
Weld Metals ◽  
Welding Arc

The behavior of nitrogen into the dissimilar joining metal between AISI 304 and AISI 316L Austenitic stainless steel during gas tungsten are welding process was investigated. Studied by using an arc nitrogen atmosphere – controlling in chamber. The relations between nitrogen content of the dissimilar weld metal and the welding parameters, such as the welding current, welding speed, welding arc length and penetration area of weld metals were also evaluated. The results show that the nitrogen content of the weld metals decreased with an increasing welding current, and increasing penetration areas of weld metal, but scarcely depends on the welding arc length. The nitrogen content of the weld metals increased with the welding speed, but decreased penetration areas of weld metals. The role of nitrogen content on the dissimilar weld metals stainless steel is further confirmed by the experimental microstructure, mechanical and corrosion behaviour of the weld metal.

A STUDY ON HYSTERETIC MODEL FOR WELD METAL AND ITS EFFECT ON BEHAVIOR OF STEEL PIPES WITH A WELDED JOINT

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4069-4074 ◽  
Author(s):  
KYONG-HO CHANG ◽  
GAB-CHUL JANG ◽  
SANG-HYONG LEE
Keyword(s):  
Cyclic Loading ◽  
Weld Metal ◽  
Welded Joint ◽  
Low Cycle Fatigue ◽  
Welding Process ◽  
Steel Structures ◽  
Steel Pipe ◽  
Hysteretic Model ◽  
Element Analysis ◽  
Weld Metals

The weld metals used in welding process influences on behavior of steel structures under monotonic and cyclic loading. Because weld metals have different characteristics than structional steels for stress-strain relationship and mechanical properties. Therefore, to predict behavior of steel structure manufactured by welding process, a hysteretic model for weld metal is necessary. In this paper, to formulate the hysteretic model for E71T-1 weld metal, tensile tests and low cycle fatigue tests were carried out. A formulated hysteretic model applied to 3-dimensional elastic-plastic finite element analysis was proposed by the authors. To investigate the effect of weld metal on behavior of steel pipe members, numerical analyses of steel pipe with a welded joint were carried out under monotonic and cyclic loading. The effect of weld metal was clarified by comparing analytical results both steel pipe with consideration of weld metal and without consideration of weld metal.

Effect of shielding gas combination on microstructure and mechanical properties of MIG welded stainless steel 316

2021 ◽  
Vol 63 (1) ◽  
pp. 97-101
Author(s):  
İsmail Açar ◽  
Behçet Gülenç
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Welding Process ◽  
Bending Test ◽  
Welding Parameters ◽  
Microstructural Properties ◽  
Shielding Gas

Abstract The quality of welded joints depends on the most optimal welding parameters and the selection of shielding gas type. The shielding gas was selected for joining stainless steels through gas metal arc welding methods by considering properties such as chemical-metallurgical interaction of shielding gas and the molten weld metal during the welding process, heat transmission capability of the gas and cost. In this study, the effect of different shielding gas combinations on the mechanical and microstructural properties of 316 austenitic stainless steel joined by the metal inert gas (MIG) welding method was investigated. In the welding process, pure argon (100 % Ar), 98.5 % Ar + 1.5 % H2 and 95 % Ar + 5 % H2 were used as shielding gases. Tensile, hardness, and bending tests were conducted to determine mechanical properties of the welded samples. In addition, metallographic examinations were carried out to detect the macrostructural and microstructural properties of weld zones. According to the results obtained from the study, the highest tensile strength was obtained from the joints welded using 100 % Ar shielding gas. When the addition of H2 into the Ar gas increased, the tensile strength of the welded samples decreased. As a result of the tensile test, fractures occurred in the base metal in all welded samples. In all welding parameters, the hardness of the weld metal was lower as compared to the heat affected zone (HAZ) and the base metal. As a result of the bending test, crack and tearing defects were found in the weld zone.

Effects of oxygen content on microstructure and impact toughness of high heat input flux-cored wire weld metals

2018 ◽  
Vol 115 (4) ◽  
pp. 410
Author(s):  
Fengyu Song ◽  
Yanmei Li ◽  
Ping Wang ◽  
Fuxian Zhu
Keyword(s):  
Grain Size ◽  
Impact Toughness ◽  
Weld Metal ◽  
Oxygen Content ◽  
Heat Input ◽  
High Heat ◽  
Cored Wire ◽  
Weld Metals ◽  
High Heat Input ◽  
The Impact

Three weld metals with different oxygen contents were developed. The influence of oxygen contents on the microstructure and impact toughness of weld metal was investigated through high heat input welding tests. The results showed that a large number of fine inclusions were formed and distributed randomly in the weld metal with oxygen content of 500 ppm under the heat input condition of 341 kJ/cm. Substantial cross interlocked acicular ferritic grains were induced to generate in the vicinity of the inclusions, primarily leading to the high impact toughness at low temperature for the weld metal. With the increase of oxygen content, the number of fine inclusions distributed in the weld metal increased and the grain size of intragranular acicular ferrites decreased, which enhanced the impact toughness of the weld metal. Nevertheless, a further increase of oxygen content would contribute to a great diminution of the austenitic grain size. Following that the fraction of grain boundary and the start temperature of transformation increased, which facilitated the abundant formation of pro-eutectoid ferrites and resulted in a deteriorative impact toughness of the weld metal.

Investigation on Impact Energy of S30403 Austenitic Stainless Steel at Different Temperatures

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Zhiwei Chen ◽  
Caifu Qian ◽  
Guoyi Yang ◽  
Xiang Li
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cross Section ◽  
Test Temperature ◽  
Impact Energy ◽  
Welded Joint ◽  
Charpy Impact ◽  
Base Plate ◽  
Charpy Impact Energy ◽  
The Impact

In this paper, a series of impact tests on S30403 austenitic stainless steel at 20/−196/−269 °C were performed to determine the effects of cryogenic temperatures on the material properties. Both base plate and welded joint including weld and heat-affected zone were tested to obtain the Charpy impact energy KV2 and lateral expansion rate at the cross section. It was found that when the test temperature decreased from 20 °C to −196 °C or −269 °C, both the Charpy impact energy KV2 at the base plate and welded joint decreased drastically. Specifically, the impact energy KV2 decreased by 20% at the base plate and decreased by 54% at the welded joint from 20 °C to −196 °C, but the impact energy of base plate and welded joint did not decrease, even increased when test temperature decreased from −196 °C to −269 °C. Either at 20 °C or −196 °C, the impact energy KV2 with 5 × 10 × 55 mm3 specimens was about 0.53 times that of the 7.5 × 10 × 55 mm3 specimens, much lower than 2/3, the ratio of two specimens’ cross section areas.

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

Effect of Ar-N2 Mixed Gas on Morphology and Microstructure of Type 316L Stainless Steel TIG Weld Metal

2011 ◽  
Vol 295-297 ◽  
pp. 1919-1924 ◽  
Author(s):  
Kuang Hung Tseng ◽  
Kai Chieh Hsien
Keyword(s):  
Stainless Steel ◽  
Weld Metal ◽  
316L Stainless Steel ◽  
Welding Process ◽  
Ferrite Content ◽  
Shielding Gas ◽  
Mixed Gas ◽  
Nitrogen Gas ◽  
Type 316L ◽  
Type 316L Stainless Steel

The aim of the present work was to investigate the effects of specific nitrogen gas additions to argon shielding gas on morphology and microstructure of austenitic stainless steel TIG welds. An autogenous TIG welding process was applied on type 316L stainless steel to produce a bead-on-plate weld. The ferrite content of weld metal was measured using a Feritscope. The results indicated that the arc voltage increase as the amount of nitrogen gas added to the argon atmosphere increases. The retained ferrite content of type 316L stainless steel TIG weld metal decreased rapidly as nitrogen gas addition to the argon shielding gas was increased.

scholarly journals Preliminary Research on Influence of Welding Parameters Strength at Welded Joints in Ribbed Reinforcing Steel

2020 ◽  
Vol 14 (3) ◽  
pp. 369-374
Author(s):  
Željko Bilić ◽  
Ivan Samardžić ◽  
Nedjeljko Mišina ◽  
Katarina Stoić
Keyword(s):  
Welded Joint ◽  
Welding Process ◽  
Welding Parameters ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Butt Welding ◽  
Control Interface ◽  
High Level ◽  
Non Destructive

As already known, no proper control or process control parameter which absolutely guarantees a high level quality of joints made by electro-resistive welding has been established so far, especially when all possible parameters are taken into account during the welding process. Due to the process of butt-welding being very short-lived, ensuring quality of the joints is a difficult and under-researched problem. The application of non-destructive testing methods to the control interface joints is also not reliable. Therefore, further research in this area should concentrate on studying the influence of basic welding parameters, and calculating their direct or indirect impact can serve to achieve a highquality welded joint with for practice sufficient accuracy.

Study on Weldablity of Dissimilar Steel between 16MnR and S31803

2011 ◽  
Vol 391-392 ◽  
pp. 768-772 ◽  
Author(s):  
Li Yang ◽  
Zhan Zhe Zhang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Impact Toughness ◽  
Weld Metal ◽  
Welded Joint ◽  
Optical Microscope ◽  
Dissimilar Steel ◽  
Austenite Content ◽  
Mechanical Properties And Corrosion ◽  
The Impact

The weldablity of dissimilar steel between 16MnR and S31803 was analyzed and researched. By means of optical microscope (OM), the microstructure of the weld joint was investigated, which is welded by tungsten inert gas arc backing welding (GTAW) and manual arc filling welding (SMAW). The mechanical properties and corrosion resistance of the welded joint was also tested and studied. Results indicate that austenite and acicular ferrite distribute uniformly in the weld metal, which strengths the toughness and ductility of the joint. The austenite content in weld is higher than that in over-heated zone of S31803.The SMAW joint structure is coarsening than that of GTAW and has more austenite content. It is also observed that there are a decarburization layer and a carbon-enriched zone nearby the fusion line. And very small amounts of the third phase of harmful metal phase are found in the fusion zone of S31803 side. The welded joint shows the excellent mechanical properties and corrosion resistance. The impact toughness of the weld metal is higher than in HAZ of 16MnR side, and the impact toughness at GTAW side and in HAZ is superior to the SMAW side.

scholarly journals Microstructure and Impact Toughness of Local-Dry Keyhole Tungsten Inert Gas Welded Joints

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1638 ◽  
Author(s):  
Shuwan Cui ◽  
Zhiyong Xian ◽  
Yonghua Shi ◽  
Baoyi Liao ◽  
Tao Zhu
Keyword(s):  
Impact Toughness ◽  
Weld Metal ◽  
Welded Joint ◽  
Coincidence Site Lattice ◽  
Random Phase ◽  
Inert Gas ◽  
Phase Boundaries ◽  
Site Lattice ◽  
Underwater Welding ◽  
The Impact

In this paper, the microstructure and impact toughness of a S32101 duplex stainless steel underwater local-dry keyhole tungsten inert gas welded joint were studied. The impact toughness value of the underwater weld metal reached 78% of the onshore weld metal, which is in accordance with the underwater welding standards. The proportion of austenite in the underwater weld metal was 0.9% lower than that of the onshore weld metal. The proportion of the Σ3 coincidence site lattice boundaries and random phase boundaries in the underwater weld metal, which significantly influence the impact toughness of the weld metal, were smaller than that of the onshore weld metal.

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