scholarly journals Laser welding of panel joints of stainless steel heat exchangers

2019 ◽  
Vol 91 (7) ◽  
pp. 7-19 ◽  
Author(s):  
Aleksander Lisiecki ◽  
Piotr Wójciga ◽  
Agnieszka Kurc-Lisiecka ◽  
Michał Barczyk ◽  
Sonia Krawczyk

Results of study on the laser welding process of pillow plates heat exchangers are presented in the article. The influence of basic parameters of CO2laser welding on the quality of overlap joints of AISI 304 stainless steel plates 2.0 and 4.0 mm thick was determined. The range of optimal parameters of welding, providing the highest quality and high mechanical performance of the test joints was determined. The technological conditions elaborated during the study were applied for manufacturing of the real pillow plates heat exchangers with dimensions of 1.5 x 1.5 m.

Author(s):  
Gurinder Singh Brar ◽  
Manpreet Singh ◽  
Ajay Singh Jamwal

AISI 304 stainless steel is one of the grades of steel widely used in engineering applications particularly in chemical equipments, food processing, pressure vessels and paper industry. Friction crush welding (FCW) is type of friction welding, where there is a relative motion between the tool and work-piece. In FCW process, the edges of the work-piece to be joined are prepared with flanged edges and then placed against each other. A non-consumable friction disc tool will transverse with a constant feed rate along the edges of the work-piece, which leads to welding. The joint is formed by the action of crushing a certain amount of additional flanged material into the gap formed by the contacting material. The novelty of present work is that FCW removes the limitations of friction stir welding and Steel work pieces can be economically welded by FCW. Taguchi method of Design of Experiments (DOE) is used to find optimal process parameters of Friction Crush Welding (FCW). A L9 Orthogonal Array, Signal to Noise ratio (S/N) and Analysis of Variance are applied to analyze the effect of welding parameters (welding speed, RPM, tool profile) on the weld properties like bond strength. Grain refinement takes place in friction crush welding as is seen in friction stir welding. Friction crush welding process also has added advantage in reducing distortion and residual stresses.


2012 ◽  
Vol 626 ◽  
pp. 518-522
Author(s):  
Hsuan Liang Lin ◽  
Zhau Hong Hsu ◽  
Wun Kai Wang

The purpose of this work is to investigate the effects of activating flux on the penetration, depth-to-width ratio (DWR), angular distortion and hardness of Inconel 718 alloy and AISI 304 stainless steel (SS) dissimilar welds in the tungsten inert gas (TIG) welding process. In the activated TIG (A-TIG) process, the single component fluxes such as SiO2, NiO, MoO3 and MoS2 and the mixed component fluxes that using 50 % of each single component flux to create six new mixtures were used in the experiment. The experimental results showed that the A-TIG welds coated with 100% SiO2 flux was provided with best DWR of dissimilar welds. In addition, the experimental procedure of A-TIG welding process not only produced a significant increase in penetration and DWR of weld bead, but also improved the angular distortion and hardness of Inconel 718 alloy and AISI 304 SS dissimilar welds.


2011 ◽  
Vol 117-119 ◽  
pp. 402-408
Author(s):  
Shazarel Shamsudin ◽  
Phoon Chee Yoon

Product with low cost, lightweight and enhanced mechanical properties were the main reasons welding dissimilar materials thrived by most of the industries. The laser welding technique which has high-energy density beam was found suitable of carrying this task. This paper attempts to investigate welding of AISI 304 stainless steel to AISI 1008 steel through Nd:YAG pulse laser method. The main objective of this study was to find out the weldability of these materials and investigate the mechanical properties of the welded butt joints. Peak power, pulse duration and weld speed combinations were carefully selected with the aims of producing weld with a good tensile strength, minimum heat affected zone (HAZ) and acceptable welding profile. Response surface methodology (RSM) approach was adopted as statistical design technique for tensile strength optimization. Statistical based mathematical model was developed to describe effects of each process parameters on the weld tensile strength and for response prediction within the parameter ranges. The microstructure of the weld and heat affected zones were observed via optical microscope. The results indicate the developed model can predict the response within ±9% of error from the actual values.


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