Microstructural and Mechanical Characterization of a TRIP-800 Steel Welded By Laser-CO2 Process

2010 ◽  
Vol 1276 ◽  
Author(s):  
G. Y. Perez-Medina ◽  
P. Zambrano ◽  
H. F. López ◽  
F. A. Reyes-Valdés ◽  
V. H. López-Cortés
Keyword(s):  
Laser Welding ◽  
Automotive Industry ◽  
Annealing Temperature ◽  
Process Condition ◽  
Welding Process ◽  
Controlled Cooling ◽  
The Impact ◽  
Holding Temperature ◽  
Laser Welding Process

AbstractThis paper presents results on the impact of Laser CO2 process variables on the weldability, phase transformations and tensile properties of a TRIP800 Steel. The microstructure of this steel is comprised of ferrite, bainite and retained austenite phases. This is obtained by controlled cooling from the intercritical annealing temperature to the isothermal bainitic holding temperature. These steels have been increasingly used in the last 10 years in the automotive industry and for these materials to be used effectively; the influence of material and the CO2 laser welding process condition must be clearly understood. Hence, in this work the effect of the welding process on the resultant microstructures and on the exhibited mechanical properties is investigated. It is found that the tensile strength of welded specimens falls below 800 MPa and that the elongation becomes 15 % or lower. In turn, this clearly indicates that the implemented laser welding process leads to a reduction in the TRIP800 steel toughness.

Microstructural Characterization by Color Tint Etching of a TRIP-800 Steel Welded by Laser CO2 Process.

2012 ◽  
Vol 1381 ◽  
Author(s):  
G.Y. Pérez-Medina ◽  
P. Zambrano ◽  
H.F. López ◽  
F.A. Reyes-Valdés ◽  
V H. López-Cortés
Keyword(s):  
Retained Austenite ◽  
Process Condition ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Blue Color ◽  
X Ray Diffraction ◽  
Controlled Cooling ◽  
X Ray ◽  
The Impact ◽  
Holding Temperature

ABSTRACTThis paper presents results on the impact of Laser CO2 process variables on the weldability, phase transformations and exhibited tensile properties in a TRIP800 Steel. The microstructures of this steel consist of ferrite, bainite, martensite, and substantial amount of retained austenite, which is obtained by controlled cooling from the intercritical anneling temperature to the isothermal bainitic holding temperature. These steel has been increasingly used in the last 10 years in the automotive industries and for these materials to be used effectively, the influence of material and the Laser CO2 process condition must be clearly understood. Hence, in this work the effect of the welding process on the resultant microstructures and on the exhibited mechanical properties was investigated. Color tint etching applied in welded for AHSS help us to know the phase transformation, the colors of each phase viewed under the microscopy. The weld was etching with Klemm´s 1 solution, in this work; it was found that the bainite is clearly identify by blue color, the martensite brown, yellow ferrite and the retained austenite white. Additional X ray Diffraction (XRD) is employed in characterization to estimate the quantity of retained austenite.

Microstructure Characterization of AZ31B Mg Alloy Welds Processed by Nd:YAG Laser Welding

2017 ◽  
Vol 898 ◽  
pp. 1051-1055 ◽  
Author(s):  
Hong Tao Liu ◽  
Ruo Chao Wang ◽  
Qing Liu ◽  
Ji Xue Zhou ◽  
Yan Fei Chen ◽  
...  
Keyword(s):  
Laser Welding ◽  
Nd:Yag Laser ◽  
Energy Dispersive Spectrometer ◽  
Base Material ◽  
Welding Process ◽  
Microstructure Characterization ◽  
Columnar Grains ◽  
Equiaxed Grains ◽  
Laser Welding Process

The Nd:YAG laser welding process of AZ31B alloys was performed by using the six-axis robot in this work. The microstructure characterization of AZ31B auto-welded joints was studied by using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The laser welding process resulted in the formation of equiaxed grains in the center of the fusion zone (FZ) and columnar grains near the FZ boundary, meanwhile some eutectic β-Mg17Al12 particles were observed in the microstructure. No clear heat affected zone (HAZ) was observed in the welded AZ31B joint. Furthermore, some pores were observed in the base material (BM) and FZ.

Segmentation of Molten Pool Infrared Images Using Morphology during High Power Disk Laser Welding

2012 ◽  
Vol 201-202 ◽  
pp. 91-94
Author(s):  
Yan Xi Zhang ◽  
Xiang Dong Gao
Keyword(s):  
Laser Welding ◽  
High Power ◽  
Molten Pool ◽  
Welding Process ◽  
Histogram Equalization ◽  
Welding Quality ◽  
Infrared Images ◽  
Traditional Methods ◽  
Disk Laser ◽  
Laser Welding Process

Configuration of a molten pool is related to the laser welding quality. Analyzing the configuration of a molten pool is important to monitor the laser welding process. This paper proposes a method of segmentation of a molten pool and its shadow during high power disk laser welding, consequently provides the groundwork for reconstruction of the molten pool and analysis of welding quality. Subsection linear stretching histogram equalization was applied to enhance the contrast of the original images firstly, and then edge detection was used to highlight the edges. After that we used the morphology filtering method to produce the segmentation mask, and then combined the mask with the original images to get the final segmentation results. Also, the proposed method was compared with other traditional methods. The experimental results showed that our method not only could give better segmentation results and process large quantities images automatically, but also overcame the less-segmentation problems of traditional methods.

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