scholarly journals Influence of Laser-Welding on Microstructure and Corrosion Properties of Twinning-Induced Plasticity (TWIP) Steel

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4315 ◽  
Author(s):  
Chengcheng Xu ◽  
Youkang Zhang ◽  
Wanlei Liu ◽  
Ying Jin ◽  
Lei Wen ◽  
...  
Keyword(s):  
Laser Welding ◽  
Welding Speed ◽  
Welded Joints ◽  
Twip Steel ◽  
Coincidence Site Lattice ◽  
Kelvin Probe ◽  
Electron Backscattered Diffraction ◽  
Corrosion Properties ◽  
Superior Corrosion Resistance ◽  
Mechanical Properties And Corrosion

The effect of welding speed on microstructure, mechanical properties, and corrosion properties of laser-assisted welded joints of a twinning-induced plasticity (TWIP) steel was investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) analysis, electrochemical test, and micro-area scanning Kelvin probe test (SKP). The results reveal that the welded joints, with a fully austenitic structure, are obtained by laser welding. In addition, the preferred orientation of grains in fusion zone (FZ) increased with the increase of welding speed. Additionally, the coincidence site lattice (CSL) grain boundaries of FZ decreased with increasing welding speed. However, potentiodynamic polarization and SKP results demonstrated that the welding speed of 1.5 m/min renders superior corrosion resistance. It can also be inferred that the corrosion properties of the welded joints are related to the grain size and frequency of CSL grain boundary in FZ.

scholarly journals The Evolution and Distribution of Microstructures in High-Energy Laser-Welded X100 Pipeline Steel

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1762 ◽  
Author(s):  
Gang Wang ◽  
Limeng Yin ◽  
Zongxiang Yao ◽  
Jinzhao Wang ◽  
Shan Jiang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Laser Welding ◽  
Grain Boundaries ◽  
Welded Joints ◽  
Pipeline Steel ◽  
High Energy ◽  
Electron Backscattered Diffraction ◽  
Boundary Density ◽  
Energy Beam ◽  
X100 Pipeline Steel

High-energy beam welding was introduced for pipeline steel welding to reduce pipeline construction costs and improve the efficiency and safety of oil and gas transportation. Microstructures and their distribution in X100 laser-welded joints, which determine the joints’ strength and toughness, are discussed in this paper. Welded joints were prepared by an automatic 10,000-watt robot-based disc laser-welding platform for 12.8 mm thick X100 pipeline steel. Then, the grain, grain boundary, orientation, and distribution pattern of each zone of the welded joints were studied by optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and electron backscattered diffraction (EBSD) analysis techniques. The results showed that the grain boundary density, contents of the high-angle and low-angle grain boundaries, distribution states, and evolution trends of coincident site lattice (CSL) grain boundaries were essentially the same in each zone from the base metal (BM) to the weld of the X100 pipeline steel laser-welded joint. The relative content of grain boundaries above 55°, which were composed of the Σ3 type CSL grain boundary, showed a considerable impact on the mechanical properties of the joint. The content of twin grain boundaries was closely related to the thermal cycles of laser welding, and the effect of the cooling rate was greater than that of the process of austenization.

scholarly journals Effect of Laser Welding Parameters on Formation of NiTi Shape Memory Alloy Welds

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Wang ◽  
Xiaohong Yang ◽  
Hongguang Li ◽  
Fuzhong Cong ◽  
Yongbing Liu
Keyword(s):  
Laser Welding ◽  
Shape Memory ◽  
Welding Speed ◽  
Welded Joints ◽  
Heat Input ◽  
Continuous Wave ◽  
Niti Alloy ◽  
Welding Parameters ◽  
Niti Shape Memory Alloy ◽  
Flat Plates

In this work experimental trials of welding of NiTi flat plates with 2.0 mm thickness were conducted using a 4.5 kW continuous wave (CW) Nd:YAG laser. The influences of laser output power, welding speed, defocus amount and side-blow shielding gas flow rate on the morphology, welding depth and width, and quality of the welded seam were investigated. Meanwhile, the effects of heat input on the mechanical and functional properties of welded joints were studied. The results show that laser welding can take better formation in NiTi alloys. The matching curves with laser power and welding speed affecting different formation of welds were experimentally acquired, which can provide references for laser welding and engineering application of NiTi alloy. The heat input has obvious effects on the ultimate tensile strength (UTS) and shape memory behavior of the welded joints.

Effect of laser welding speed on pore formation in AA 6061 T6 alloy

2020 ◽  
Vol 62 (10) ◽  
pp. 979-984
Author(s):  
Emine Gündoğdu İş ◽  
Erhan Akman ◽  
Muharrem Yilmaz ◽  
Polat Topuz
Keyword(s):  
Laser Welding ◽  
Welding Speed ◽  
Welded Joints ◽  
Pore Formation ◽  
Weld Seam ◽  
Welding Process ◽  
Tensile Tests ◽  
Fiber Laser Welding ◽  
Thick Plates ◽  
Hardness Tests

Abstract In this study, 6 mm thick plates of Al 6061 T6 alloy are joined by laser welding at four welding speeds (40 mm × s-1, 35 mm × s-1, 25 mm × s-1, and 20 mm × s-1). The welded joints are made using a 4000 W fiber laser welding machine. The effect of laser welding speed on the pores formed in the weld seam was investigated. In this manner, it was found that with a change in laser welding speed the amount of pores formed in the structure also changed. In addition, after the welding process, macroscopic examinations, tensile tests and the hardness tests were made. As a result of the experiments performed, it was determined that, the laser welding speed was highly effective for pore formation.

scholarly journals Effect of PWHT on Laser-Welded Duplex Stainless Steel

2020 ◽  
Vol 99 (7) ◽  
pp. 185s-202s ◽  
Author(s):  
APARECIDA SILVA MAGALHÃES ◽  
◽  
CHARLES HENRIQUE XAVIER MORAIS MAGALHÃES ◽  
LEONARDO BARBOSA GODEFROID ◽  
GERALDO LÚCIO DE FARIA ◽  
...  
Keyword(s):  
Laser Welding ◽  
Welded Joints ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Corrosion Properties ◽  
Welding Condition ◽  
Heat Treated ◽  
Different Temperatures ◽  
Isothermal Heat Treatments ◽  
Pulp And Paper Industries

The welded joints of duplex stainless steels (DSSs) have been widely used in petrochemical, nuclear, pulp, and paper industries. Welds require a good, superficial finishing and a combination of mechanical and corrosion properties in these types of high-quality, demanding applications. Even though laser welding promotes narrow weld beads and a small heat-affected zone, when it is applied to DSSs, it can produce dangerous microstructural discontinuities. In this context, the effects of subsequent heat treatments on the microstructure, corrosion resistance, microhardness, and tensile proper-ties of DSS laser-welded joints are investigated. In this study, samples of UNS S32304 DSS were submitted to two different conditions of laser welding. Subsequently, the plates submitted to the best welding condition were subjected to isothermal heat treatments at different temperatures (850°, 950°, 1050°, and 1150°C) for 10 min. Then they were microstructurally characterized. Phase fraction measurements and microhardness tests were performed. Based on the obtained results, postweld heat-treated samples at 1150°C, which is the best condition, were subjected to corrosion and tensile tests. It was possible to conclude the corrosion prop-erties of the welded joint were significantly improved after the heat treatment. However, the mechanical behavior was strongly influenced by the presence of volumetric discontinuities and intermetallic compounds, which considerably deteriorated the mechanical strength of the material.

scholarly journals Zn-Co-CeO2 vs. Zn-Co Coatings: Effect of CeO2 Sol in the Enhancement of the Corrosion Performance of Electrodeposited Composite Coatings

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Healing Rate ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Self Healing ◽  
Kelvin Probe ◽  
Artificial Defect ◽  
Volta Potential ◽  
Superior Corrosion Resistance ◽  
The Stability

Electrodeposition and characterization of novel ceria-doped Zn-Co composite coatings was the main goal of this research. Electrodeposited composite coatings were compared to pure Zn-Co coatings obtained under the same conditions. The effect of two ceria sources, powder and home-made sol, on the morphology and corrosion resistance of the composite coatings was determined. During the electrodeposition process the plating solution was successfully agitated in an ultrasound bath. The source of the particles was found to influence the stability and dispersity of plating solutions. The application of ceria sol resulted in an increase of the ceria content in the resulting coating and favored the refinement from cauliflower-like morphology (Zn-Co) to uniform and compact coral-like structure (Zn-Co-CeO2 sol). The corrosion resistance of the composite coatings was enhanced compared to bare Zn-Co as evidenced by electrochemical impedance spectroscopy and scanning Kelvin probe results. Zn-Co doped with ceria particles originating from ceria sol exhibited superior corrosion resistance compared to Zn-Co-CeO2 (powder) coatings. The self-healing rate of artificial defect was calculated based on measured Volta potential difference for which Zn-Co-CeO2 (sol) coatings exhibited a self-healing rate of 73.28% in a chloride-rich environment.

scholarly journals Influence of Shielding Gas on Microstructure and Properties of GMAW DSS2205 Welded Joints

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2671
Author(s):  
Xin-Yu Zhang ◽  
Xiao-Qin Zha ◽  
Ling-Qing Gao ◽  
Peng-Hui Hei ◽  
Yong-Feng Ren
Keyword(s):  
Corrosion Resistance ◽  
Welded Joints ◽  
Welded Joint ◽  
Crystal Defects ◽  
Shielding Gas ◽  
Electrochemical Tests ◽  
Corrosion Resistance Property ◽  
Mechanical Properties And Corrosion ◽  
Ar Gas ◽  
Welded Seam

In the present study, the microstructures and properties of DSS 2205 solid wire MIG welded samples prepared in different shielding gases (pure Ar gas, 98%Ar + 2%O2 and 98%Ar + 2%N2) were investigated for improving the weldability of DSS 2205 welded joint. The work was conducted by mechanical property tests (hardness and tensile test) and corrosion resistance property tests (immersion and electrochemical tests). The results show that adding 2%O2 into pure Ar gas as the shielding gas decreases crystal defects (faults) and improves the mechanical properties and corrosion resistance of the welded joints. Phase equilibrium and microstructural homogeneity in welded seam (WS) and heat-affected zone (HAZ) can be adjusted and the strength and corrosion resistance of welded joints increased obviously by adding 2%N2 to pure Ar gas as the shielding gas. Compared with DSS 2205 solid wire MIG welding in 98%Ar + 2%O2 mixed atmosphere, the strength and corrosion resistance of welded joints are improved more obviously in 98%Ar + 2%N2 mixed atmosphere.

The effect of subsequent laser processing on the properties of welded joints made by pulsed laser welding

2021 ◽  
pp. 1-7
Author(s):  
A. V. Bogdanov ◽  
B. V. Buketkin ◽  
A. A. Kholopov ◽  
A. V. Perestoronin ◽  
R. Galiullin
Keyword(s):  
Laser Welding ◽  
Welded Joints ◽  
Laser Processing ◽  
Pulsed Laser ◽  
Pulsed Laser Welding

Mechanical and Corrosion Properties of VT6 Titanium Alloy after Irradiation with Helium and Aluminum Lons

2021 ◽  
Vol 887 ◽  
pp. 229-234
Author(s):  
Viktor V. Ovchinnikov ◽  
Svetlana V. Yakutina ◽  
Nadezhda V. Uchevatkina
Keyword(s):  
Titanium Alloy ◽  
Ion Irradiation ◽  
Structural Phase ◽  
High Dose ◽  
Corrosion Properties ◽  
Average Grain Size ◽  
Aluminum Implantation ◽  
Modified Surface ◽  
Mechanical And Corrosion Properties ◽  
Mechanical Properties And Corrosion

The effect of high-dose aluminum implantation on the structural-phase state of the surface layer of titanium alloy VT6 with a fine structure (average grain size 2.3 μm) on the mechanical and corrosion properties has been investigated. It is shown that, as a result of ion irradiation, polyphase implanted layers based on α-titanium grains are formed, containing an intermetallic Ti3Al phase along the grain boundaries of α-titanium. The modified surface layers are characterized by improved mechanical properties and corrosion resistance. The noted effect is enhanced by the use of preliminary helium implantation with a dose of 1.3 × 1017 ion / cm2.

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