scholarly journals Mechanical and Microstructural Investigations of the Laser Welding of Different Zinc-Coated Steels

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 91 ◽  
Author(s):  
Eva Zdravecká ◽  
Ján Slota
Keyword(s):  
Mechanical Properties ◽  
Laser Welding ◽  
Heat Affected Zone ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Tensile Tests ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Tailor Welded Blanks ◽  
Carbon Microalloyed

Tailor welded blanks (TWB) represent an anisotropic and non-homogenous material. The knowledge of the mechanical properties and microstructure of the fusion zone and heat-affected zone (HAZ) obtained with laser welding is essential to ensure the reliability of the process. In this paper, laser-welded hot-dip Zn-coated low carbon microalloyed steels with different thickness and mechanical properties were used. The mechanical properties of the laser-welded blanks were determined by tensile tests and formability by Erichsen cupping tests. In addition, the pore formation during the laser welding process was analyzed. The microstructural analysis confirmed the formation of the favorable structure of the weld metal and the heat-affected zone without the presence of martensite. The obtained results showed that it is possible to produce TWBs with suitable mechanical properties by laser welding.

Effect of Nb and V in the Development of Texture and Plastic Strain Ratio in Low Carbon Microalloyed Steels Produced by A.S.T. Technology

2005 ◽  
Vol 500-501 ◽  
pp. 279-286
Author(s):  
Carlo Mapelli ◽  
Roberto Venturini ◽  
Antonio Guindani
Keyword(s):  
Mechanical Properties ◽  
Strain Ratio ◽  
Tensile Tests ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Plastic Strain Ratio ◽  
Steel Technology ◽  
Back Scattering ◽  
Carbon Microalloyed ◽  
Hot Rolled

The effects of Nb and V on the anisotropy and textures featuring the hot rolled low carbon microalloyed steels produced by A.S.T. (Arvedi Steel Technology) have been studied as a function of the final coiling temperatute Tcoiling. Mechanical properties and r-values for twelve steels have been determined through tensile tests performed on three main different directions: 0°, 45°, 90° to the rolling one. The samples have been analysed by EBSD (Electron Back Scattering Diffraction) to identify the textures developed during the process. The relations among the chemical composition of the steels (i.e. C, N, Nb, V contents), the mechanical properties, the temperature during the coiling operations, the textures and the formability properties have been pointed out.

Study of heat-affected zone and mechanical properties of Nd-YAG laser welding process of thin titanium alloy sheet

2016 ◽  
Vol 1 (2) ◽  
pp. 51-58 ◽  
Author(s):  
Grzegorz Krolczyk ◽  
Aleksandar Sedmak ◽  
Uday Kumar ◽  
Somnath Chattopadhyaya ◽  
A. K. Das ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Laser Welding ◽  
Heat Affected Zone ◽  
Welding Process ◽  
Alloy Sheet ◽  
Yag Laser ◽  
Laser Welding Process

scholarly journals New Technology to Produce 1 GPa Low Carbon Microalloyed Steels from Cast Strip

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 662 ◽  
Author(s):  
Andrii Kostryzhev ◽  
Olexandra Marenych
Keyword(s):  
Mechanical Properties ◽  
Global Economy ◽  
New Technology ◽  
Carbon Steels ◽  
Thin Strip ◽  
Microalloyed Steels ◽  
Accelerated Cooling ◽  
Low Carbon ◽  
Elongation To Failure ◽  
Carbon Microalloyed

Global economy requires steel with further increasing mechanical properties and simultaneously decreasing price. In mass manufacturing three major methods can be used to increase strength: (i) increase microalloying element additions (increases cost), (ii) decrease deformation temperature and (iii) increase cooling rate after high temperature processing (both can be challenging for equipment). Thin strip casting is an effective way to reduce cost as it brings a reduction in number of deformation passes and shortens the production line. However, the mechanical properties can be missed due to insufficient microstructure development. In this article, we investigate a recently proposed technology based on Austenite Conditioning followed by Accelerated Cooling and Warm Deformation (AC2WD). Two low carbon steels microalloyed with either 0.012Ti or 0.1Mo-0.064Nb-0.021Ti (wt.%) were subjected to three processing modifications of the AC2WD-technology with two, one or no deformation of cast microstructure in the austenite temperature field. The Ti- and MoNbTi-steels exhibited 685–765 MPa and 880–950 MPa of the yield stress, 780–840 MPa and 1035–1120 MPa of tensile strength, and 20–30% and 22–24% of elongation to failure, respectively. The nature of strengthening mechanisms associated with the AC2WD-technology is discussed on the basis of detailed microstructure characterisation.

Effect of Cold-Wire Addition in the TSAW Process on Microstructure and Mechanical Properties of the HAZ of X70 Microalloyed Pipeline Steel

2016 ◽  
Author(s):  
Mohsen Mohammadijoo ◽  
Stephen Kenny ◽  
Laurie Collins ◽  
Hani Henein ◽  
Douglas G. Ivey
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Pipeline Steel ◽  
Microstructural Analysis ◽  
Research Work ◽  
High Heat ◽  
Impact Testing ◽  
Microalloyed Steels ◽  
Cold Wire ◽  
High Heat Input

Microalloyed steels can achieve a good combination of strength and toughness through appropriate alloy design and thermomechanical controlled processing (TMCP). However, the mechanical properties can deteriorate as a result of the high heat input and thermal cycles that the steel experiences during welding. It is generally accepted that the portion of the heat affected zone (HAZ) adjacent to the fusion line, i.e., the coarse grain heat affected zone (CGHAZ), which is characterized by coarse grains and martensite-austenite (M-A) constituents, is the region with poorer toughness relative to the rest of the steel. In the present research work, modification to the conventional tandem submerged arc welding (TSAW) process is carried out by the addition of a cold wire during welding (CWTSAW), which induces changes to the geometry and properties of the weld joint. Microstructural analysis, mechanical property investigation and geometry analysis indicate overall improvement in the weld and the HAZ properties after cold wire addition. These improvements are explained in terms of an increase in the deposition rate and a decrease in the amount of heat introduced to the weldment. An X70 microalloyed steel was welded using both TSAW and CWTSAW processes. Charpy-V-notch impact testing and microhardness testing showed improvement in the HAZ mechanical properties for CWTSAW samples relative to TSAW samples. Microstructural analysis, using both optical microscopy and scanning electron microscopy (SEM), indicated the formation of finer prior austenite grains (PAG) and less M-A constituent within the CGHAZ of the CWTSAW samples. These improvements are due to lower actual heat introduced to the weldment and a relatively faster cooling rate.

scholarly journals Evolution of Microstructure and Precipitation State During Thermomechanical Processing of a Low Carbon Microalloyed Steel

2012 ◽  
Vol 18 (S5) ◽  
pp. 119-120
Author(s):  
P. Valles ◽  
M. Gómez ◽  
S. F. Medina ◽  
A. Pastor ◽  
O. Vilanova
Keyword(s):  
Mechanical Properties ◽  
Acicular Ferrite ◽  
Thermomechanical Processing ◽  
Transformation Products ◽  
Microalloyed Steels ◽  
Accelerated Cooling ◽  
Low Carbon ◽  
Fine Grained ◽  
Increasing Demand ◽  
Carbon Microalloyed

The increasing demand of sources of energy such as oil and natural gas induces at the steel industry a development on low carbon microalloyed steels for pipeline applications in order to achieve excellent mechanical properties of strength and toughness at a reduced cost. To obtain an adequate fine-grained final structure, the strict control of thermomechanical processing and accelerated cooling is crucial. Depending on the thermomechanical processing conditions and chemical composition, pipeline steels can present different microstructures. Several authors have found that the microstructure of acicular ferrite usually provides an optimum combination of mechanical properties. Higher levels of austenite strengthening before cooling promote a refinement of final microstructure but can also restrict the fraction of low temperature transformation products such as acicular ferrite.

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