Laser Welded Joints of High-Nitrogen Austenitic Steels: Microstructure and Properties

2018 ◽  
Vol 284 ◽  
pp. 344-350 ◽  
Author(s):  
Vera V. Berezovskaya ◽  
A.V. Berezovskiy ◽  
D.H. Hilfi
Keyword(s):  
Welded Joints ◽  
Carbon Dioxide Laser ◽  
Continuous Wave ◽  
High Strength ◽  
Tensile Tests ◽  
Wave Mode ◽  
Austenitic Steels ◽  
Maximum Output ◽  
High Nitrogen ◽  
Corrosion Properties

High nitrogen austenitic steels are used as structural materials required possessing high strength and fracture toughness. The present study is concerned with the characteristic features (shape, size, properties and structure) of the laser welded joints in Cr-Mn-, Cr-Mn-Mo-high nitrogen steels compared to the ones of Cr-Ni-steel joint. Butt welded joints were made using carbon dioxide laser with a maximum output of 5 kW in the continuous wave mode. The hardness and tensile tests of welded joints in the air and 3.5 vol.%-solution of NaCl, as well as the theoretical studies were carried out by optical and transmission electron microscopy (TEM). The results are achieved by testing that the welded joints of HNS had satisfactory weldability, adequately high mechanical and corrosion properties. The austenite of the investigated HNS retains high stability throughout the welding cycle.

Microstructure and Mechanical Properties of Laser Beam Welds of 15CDV6 Steel

2015 ◽  
Vol 65 (4) ◽  
pp. 339 ◽  
Author(s):  
M.V.L Ramesh ◽  
P. Srinivasa Rao ◽  
V. Venkateswara Rao
Keyword(s):  
Laser Beam ◽  
Fusion Zone ◽  
Carbon Dioxide Laser ◽  
Continuous Wave ◽  
Laser Beam Welding ◽  
Wave Mode ◽  
Maximum Output ◽  
Transverse Tensile ◽  
Temperature Impact ◽  
Continuous Wave Mode

<p>The present study is concerned with laser beam welding of 15CDV6 steel, that is in the hardened (quenched and tempered) condition before welding. Autogenously butt-welded joints are made using carbon dioxide laser with a maximum output of 3.5 kw in the continuous wave mode. Weld microstructure, microhardness measurement across the weldment, transverse tensile properties, and room temperature impact properties of the weldment have been evaluated. The fusion zone exhibits a epitaxial grain growth. The microstrutural features of heat-affected zone and fusion zone vary, due to different thermal cycles for which these were subjected during welding. The average weld metal hardness was 480 Hv. The observed hardness distribution across the welds were correlated with the microstructures. The welds exhibited lower toughness of 50 joules as compared to parent metal of 55 joules and the tensile strength values of the welded specimens are close to that obtained for sheet specimens.</p><p><strong>Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 339-342, DOI: http://dx.doi.org/10.14429/dsj.65.8749</strong></p>

Does a Pulsed Mode Offer Advantages Over a Continuous Wave Mode for Excisional Biopsies Performed Using a Carbon Dioxide Laser?

2012 ◽  
Vol 70 (8) ◽  
pp. 1781-1788 ◽  
Author(s):  
Valerie G.A. Suter ◽  
Hans Jörg Altermatt ◽  
Thomas Dietrich ◽  
Peter A. Reichart ◽  
Michael M. Bornstein
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Laser ◽  
Continuous Wave ◽  
Wave Mode ◽  
Pulsed Mode ◽  
Continuous Wave Mode

IMPACT TENSILE PROPERTIES OF YAG LASER WELDED BUTT JOINTS MADE BY DIFFERENT STEEL SHEETS FOR VEHICLES

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1712-1717
Author(s):  
Y. TAKAHASHI ◽  
M. DAIMARUYA ◽  
H. KOBAYASHI ◽  
H. TSUDA ◽  
H. FUJIKI
Keyword(s):  
Tensile Properties ◽  
Welded Joints ◽  
Testing Machine ◽  
High Strength ◽  
Tensile Tests ◽  
Butt Joints ◽  
Yag Laser ◽  
Steel Sheets ◽  
Static Tensile ◽  
The Impact

The tensile properties of YAG laser welded butt joints using different high strength steel sheets with a tensile strength of 270 MPa, 590 MPa and 980 MPa (denoted HR270, HR590 and HR980, respectively) were investigated at static and dynamic rates, together with the three kinds of laser welded joints made by the same steel sheets. The impact tensile tests were performed by using the vertical type of split Hopkinson tension bar apparatus, while the static tensile tests were carried out using a universal testing machine INSTRON5586. The impact tensile strengths were significantly increased in comparison with the static ones due to the effect of strain rate, which might be the contribution of the part of HR270 base metal. And in both of static and impact tests, the fracture strains of HR270-HR590 joint, HR270-HR980 joint and HR590-HR980 joint were about one half of the fracture strains observed in the same steel welded joints of HR270-HR270, HR270-HR270 and HR590-HR590, respectively.

scholarly journals Passively Q-Switched and Mode-Locked Er3+-Doped Ring Fiber Laser with Pulse Width of Hundreds of Picoseconds

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 560
Author(s):  
Ji Wang ◽  
Wenwu Zhang ◽  
Tianrun Zhang
Keyword(s):  
Fiber Laser ◽  
Continuous Wave ◽  
Average Power ◽  
Basic Research ◽  
Single Mode ◽  
Frequency Stability ◽  
Wave Mode ◽  
Switching Frequency ◽  
Maximum Output ◽  
Power Instability

Greatly improving the energy of a single mode-locked pulse while ensuring the acquisition of the width of short pulses will contribute to the application of mode-locked pulse in basic research, such as precision machining. This report has investigated a Q-switched and mode-locked (QML) erbium doped ring fiber laser based on the nonlinear polarization rotation (NPR) technology and a mechanical Q-switched device. Without the working of the mechanical Q-switched device, the fiber laser exported the continuous-wave mode-locked (CWML) pulse, with a width of 212.5 ps, and a repetition frequency of 81.97 MHz. For the CWML operation, the maximum output average power is 25.7 mW, and the energy is only 0.31 nJ. For the QML operation, 18.03 mW average power is achieved at the Q-switching frequency of 100 Hz. The energy of the QML pulse is increased by over 1100 times to 360.6 nJ. The width of the QML pulse is 203.1 ps measured by an autocorrelation curve, with the time-band product (TBP) being 0.598. The power instability is 0.5% (RMS) and 0.7% (RMS), respectively, for CWML and QML operation within 120 min. Furthermore, the spectral signal-to-noise ratio is about 60 dB. For the QML operation, the power instability is 0.48% (RMS) within 60 s and 0.37% (RMS) within 10 s. After frequency stabilization, the frequency fluctuation is ±100 Hz in the long-term of 1200 s, with the frequency stability (FS) calculated to be 2.44 × 10−6. It indicates that the QML fiber laser has good power stability and frequency stability.

Structure and Phase Transformations in High Nitrogen and High Interstitial Steels of Different Alloying Systems - Short Review

2021 ◽  
Vol 410 ◽  
pp. 167-172
Author(s):  
Vera V. Berezovskaya ◽  
Eugeny A. Merkushkin ◽  
Ksenia A. Mamchits
Keyword(s):  
Phase Transformations ◽  
Light And Electron Microscopy ◽  
Austenitic Stainless Steels ◽  
Short Review ◽  
Austenitic Steels ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
High Nitrogen ◽  
Corrosion Properties ◽  
Excess Phases

The features of the structure evolution under thermal effect of Cr, Cr-Ni, Cr-Ni-Mn, and Cr-Mn-austenitic stainless steels with high nitrogen content and a total high content of carbon and nitrogen are analyzed. When studying the structure, we used light and electron microscopy, X-ray diffraction, dilatometry analysis and electrical resistance measurements. Fine structure and aging processes of austenite, nature and morphology of excess phases, as well as character of phase transformations and their relationship with the properties of steels have been studied. It is shown that Cr-Mn-steels with a high content of (C + N), having a homogeneous structure of austenite without excess phases, surpass Cr-Ni austenitic steels in mechanical and corrosion properties, have higher process ability than Cr-Mn-N-steel and are comparable with them in mechanical properties.

Influence of Laser Surface Melting on the Microstructure and Corrosion Behaviour of ZE41 Magnesium Alloy

2009 ◽  
Vol 618-619 ◽  
pp. 263-268 ◽  
Author(s):  
Parama Chakraborty Banerjee ◽  
R.K. Singh Raman ◽  
Y. Durandet ◽  
Grant McAdam
Keyword(s):  
Magnesium Alloy ◽  
Continuous Wave ◽  
Corrosion Behaviour ◽  
Processing Parameters ◽  
Wave Mode ◽  
Surface Melting ◽  
Laser Surface ◽  
Laser Surface Melting ◽  
Beam Diameter ◽  
Corrosion Properties

In the present study, surface melting of a magnesium alloy, ZE41 (4%-Zn, 1%-RE) is performed by an Nd:YAG laser (operating in a continuous wave mode). The degree of microstructural refinement and the depth of the laser melted zone is a strong function of laser processing parameters (laser power, beam diameter, scan rate). The corrosion properties of the laser treated and untreated zone is investigated by potentiodynamic polarization method. The microstructural changes on the surface due to laser surface melting were analysed by optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy to understand their effect on the corrosion behaviour of ZE41.

Susceptibility Study to Hydrogen Embrittlement of Welded Joints of API 5L X52 Steel in Sulphide Media

2020 ◽  
Vol 1158 ◽  
pp. 27-42
Author(s):  
Daniel Kohls ◽  
Enori Gemelli ◽  
Laercio da Silva Filho ◽  
Majorie Anacleto Bernardo
Keyword(s):  
Hydrogen Embrittlement ◽  
Base Metal ◽  
Welded Joints ◽  
Oil And Gas ◽  
Welded Joint ◽  
Welding Process ◽  
High Strength ◽  
Tensile Tests ◽  
Low Alloy Steels ◽  
X52 Steel

Pipelines for oil and gas, manufactured in high-strength low-alloy steels (HSLA), such API pipes, promote high levels of strength and fracture toughness. Therefore, it is important to ensure this high level of toughness in the welded joint. When the pipelines are exposed for many years to wet H2S environments, they can fail due to hydrogen embrittlement. Thus, it is important to evaluate the influence of different weld specifications in the susceptibility to hydrogen embrittlement. In this case, the aim of this work was to study the susceptibility to hydrogen embrittlement of API 5L X52 steel and in the welded region in wet environments. The welding was performed in the circumferential direction by GMAW process in two different specifications (with lower and higher thermal input). The susceptibility to hydrogen embrittlement was carried out according to NACE TM0177 and SSRT (slow strain rate tensile tests) test, performed according to ASTM G 129 standard. All welded joints and base metal did not show any signal of cracks and susceptibility to hydrogen embrittlement, according to the requirements of the NACE TM0177 test. According to SSRT tensile test, the results showed that the welded joints and base metal are susceptible to hydrogen embrittlement. The tensile tests exhibited a drop in the strain and necking, and higher values of yield stress. The welded joint with the lowest heat inputs employed in the welding process presented the highest susceptibility to hydrogen embrittlement.

Studies on the Corrosion Properties of High-Mn Austenitic Steels

2015 ◽  
Vol 227 ◽  
pp. 75-78 ◽  
Author(s):  
Magdalena Jabłońska ◽  
Rafał Michalik
Keyword(s):  
Materials Science ◽  
High Strength ◽  
Corrosion Current ◽  
Austenitic Steels ◽  
Manganese Steel ◽  
Nacl Solution ◽  
High Manganese ◽  
Corrosion Properties ◽  
University Of Technology ◽  
New Type

Institute of Materials Science at Silesian University of Technology since 6 years conducts researches to learn about the new dedicated for automotive, railway and military industries. Some of these materials belong to the group of AHS steels, characterized by the twinning induced plasticity (TWIP) effect. It is a new type of steel possessing both a high strength and a great plastic elongation, and an ideal uniform work hardening behaviour. It is therefore a good candidate for deep drawing applications in the automobile and railway industries. In the paper the of the three grades of high-manganese steels of was studied in 3.5% NaCl solution and in an “acid rain” solution with pH=3.5 environments using polarization experiments. The results of corrosion tests and analysis of show that a higher polarisation resistance and lower values of corrosion current density are observed for all studied steels in 3.5% NaCl solution. Spontaneous passivation ability has been shown only for one grade of high-manganese steel in 3.5% NaCl.

scholarly journals Bimodal Microstructure Obtained by Rapid Solidification to Improve the Mechanical and Corrosion Properties of Aluminum Alloys at Elevated Temperature

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 230
Author(s):  
Irena Paulin ◽  
Črtomir Donik ◽  
Peter Cvahte ◽  
Matjaž Godec
Keyword(s):  
Elevated Temperature ◽  
Aluminum Alloys ◽  
Melt Spinning ◽  
High Strength ◽  
Tensile Tests ◽  
Chemical Compositions ◽  
Corrosion Properties ◽  
Transmission Microscopy ◽  
Aa5083 Alloy ◽  
Mechanical And Corrosion Properties

The demand for aluminum alloys is increasing, as are the demands for higher strength, with the aim of using lighter products for a greener environment. To achieve high-strength, corrosion-resistant aluminum alloys, the melt is rapidly solidified using the melt-spinning technique to form ribbons, which are then plastically consolidated by extrusion at elevated temperature. Different chemical compositions, based on adding the transition-metal elements Mn and Fe, were employed to remain within the limits of the standard chemical composition of the AA5083 alloy. The samples were systematically studied using light microscopy, scanning electron, and transmission microscopy with electron diffraction spectrometry for the micro-chemical analyses. Tensile tests and Vickers microhardness were applied for mechanical analyses, and corrosion tests were performed in a comparison with the standard alloy. The tensile strength was improved by 65%, the yield strength by 45% and elongation by 14%. The mechanism by which we achieved the better mechanical and corrosion properties is explained.

Sign in / Sign up

Export Citation Format

Share Document