Thermal Cycles and Peculiar Properties of Austenite Decomposition when Laser-Hybrid Welding Steel of K60 Strength Class

2018 ◽  
Vol 284 ◽  
pp. 489-494
Author(s):  
A.I. Romantsov ◽  
M.A. Fedorov ◽  
M.A. Ivanov
Keyword(s):  
Heat Affected Zone ◽  
Strength Class ◽  
Welding Process ◽  
Hybrid Welding ◽  
Austenite Decomposition ◽  
Thermal Cycles ◽  
Engineering Structures ◽  
Laser Hybrid Welding ◽  
Laser Hybrid ◽  
Complex Phenomena

Welding is an important technology of joint in engineering structures. In addition to a residual stress influence to a quality of joint, an obstacle in welding analysis are complex phenomena including phase transformation, thermal cycle and microstructure kinetics. The influence appears in microstructure development, formation of defects and in transformation of metallurgy in a welded zone. This article experimentally defines thermal cycles and shows the results in study of peculiar properties of austenite decomposition kinetics when using the technology of laser-hybrid welding in combination with multiple arc automatic sub-merged welding. There defined the rates of cooling influencing the change of properties of welded joints from tube assortment steel of K60 strength class. We found that the result of impact of laser-hybrid welding process in a heat-affected zone is that the austenite decomposition in studied steels flows in martensite area generally. The hardness of seam metal and heat-affected zone of the studied steels is of range 350-360 HV, which increases a probability of crack-like, defects formation. We revealed the normative value of hardness, which can be provided if a metal cooling rate in laser-hybrid welding is about 20 °C/s.

Austenite Decomposition Kinetics in Laser-Hybrid Welding of Steel of Strength Class K52

2019 ◽  
Vol 946 ◽  
pp. 950-955 ◽  
Author(s):  
A.I. Romantsov ◽  
M.A. Fedorov ◽  
D.G. Lodkov
Keyword(s):  
Welded Joints ◽  
Strength Class ◽  
Defect Formation ◽  
Welding Process ◽  
Decomposition Kinetics ◽  
Hybrid Welding ◽  
Austenite Decomposition ◽  
Laser Hybrid Welding ◽  
Laser Hybrid ◽  
The Impact

A modern technology for joining materials welding is commonly used in various industries. It is a process of interaction of thermal, mechanical and metallurgical properties and behaviors. Complex phenomena, such as solidification, microstructural changes and defect formation, have a great impact on the quality of welded joints. This article presents the results of studying the features of the austenite decomposition kinetics in the application of laser-hybrid welding technology, in a combination with multi-arc automatic submerged arc welding. The cooling rates are determined, affecting the change in properties of HAZ of welded joints on pipe steel of strength class K52. Using the dilatometric method, studies were conducted and thermo-kinetic and structural diagrams were constructed. Analysis of diagrams and microstructures showed that, as a result of the impact of the laser-hybrid welding process in the area of HAZ, the decomposition of austenite occurs mainly in the martensitic zone, followed by the formation of a bainite-perlite structure, due to recrystallization from the heat generated by the facing seams.

Laser Hybrid Welding of Advanced High Strength Steels (AHSS) for Automotive Body Construction

2007 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Sergio Angotti ◽  
Armando Joaquin ◽  
Eric Stiles
Keyword(s):  
Mild Steel ◽  
Light Source ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Hybrid Welding ◽  
Advanced High Strength Steels ◽  
Laser Hybrid Welding ◽  
Laser Hybrid ◽  
Welding Processes

In response to demands for improved safety standards and fuel economy, automotive OEMs have shown an increased interest for using light weight materials with greater strength. Advanced High Strength Steels (AHSS) have gained popularity due to their superior mechanical properties and weight advantages, as compared to mild steel materials. Welding of AHSS materials remains one of the technical challenges in the successful application of AHSS in automobile structures, especially when durability of the welded structures is required. Currently, various fusion welding processes such as Metal Inert Gas (MIG), Laser and Laser Hybrid are used on mild steel applications. The Laser and Laser Hybrid weld processes continue to gain popularity in automotive applications due to their ability to provide structural integrity and manufacturing efficiency. In laser welding, only a light source is used to join materials together. In laser hybrid, both a light source and metal filler are used to join the materials. In this paper, the laser hybrid joining process on AHSS materials (DP780 and Boron) is investigated. Influence of heat from Laser Hybrid welding process and its effect on the steel is discussed.

scholarly journals Development of Plasma-Laser-Hybrid Welding Process

2011 ◽  
Vol 12 ◽  
pp. 194-200 ◽  
Author(s):  
Claus Emmelmann ◽  
Marc Kirchhoff ◽  
Nikolai Petri
Keyword(s):  
Welding Process ◽  
Hybrid Welding ◽  
Plasma Laser ◽  
Laser Hybrid Welding ◽  
Laser Hybrid
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