Friction Welding of Pipe to Plate TAKEGAMI, Hiroaki; SHINODA, Takeshi; SAITO, Tadashi ...
QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY,
2003, Volume:
21, Issue:
2
Journal Article
Open access
In welding of a thin plate, welding deformation is a severe problem. It is difficult to correct the welding deformation after welding. Therefore, the welding deformation should be avoided before or ...during welding. As the welding deformation is generated by thermal cycle during welding, it is thought low heat input joining process is efficient to decrease the welding deformation. In this study, friction welding was proposed as lower heat input welding process than arc welding. MAG welding was also carried out to compare welding deformation and heat input. However, it is difficult to compare heat input between friction welding and arc welding. Because, there in no general heat input calculation in friction welding and does not define the weld line in friction welding. To compare the heat input directly, pipe circumference was assumed to weld line and calculated heat input by simplified heat input rate, which was proposed by authors. The appearance of friction welded joint was sound and tensile tests revealed the fracture occurred at the base metal of plate. In friction welding, the deformation of plate was smaller than that in MAG welded joints. Heat input in friction welding was 10-30% in MAG welding by direct comparison for same dimension of joints. The time for welding was also smaller in friction welding. Friction welding is small deformation and efficiency process for joining of pipe and thin plate.
In this study, spheroidal graphite cast iron (FCD) with different Si content and stainless steel (SUS) were welded by the metal active gas (MAG) welding method using different types of Fe-Ni-Cr ...welding wires of different Ni and Cr equivalence. After welding, microstructure, Vickers hardness, quantitative and line analysis of alloying elements near the welding zone of each specimen were investigated. The results proved that a ledeburite layer is formed in the bonding interface between FCD and weld metals. Consequently Vickers hardness of the bonded zone was 800 to 900 HV. The widths of the ledeburite layer and heat affected zone (HAZ) was found to decrease with increasing Ni equivalent in welding wires and Si content in the FCD base metal respectively. Chromium carbide was found to precipitate in the grain boundary of weld metals using welding wire containing Cr
A Simulation Model of MAG Welding YAMAMOTO, Takeshi; TSUJI, Yoko; MIYASAKA, Fumikazu ...
QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY,
2001, Volume:
19, Issue:
4
Journal Article
Open access
In the present work, a three-dimensional (3-D), non-stationary thermal model for MAG (Metal Active Gas) welding is developed. The transient temperature distribution on the base metal is numerically ...analyzed in order to estimate the molten pool size by using a finite difference model based on the heat flow equation, and the theoretical configuration of molten pool is calculated, taking account of the balance of gravity, surface tension and arc pressure. The developed model can be applied to various welding processes such as multi-pass welding, lap welding and welding with torch weaving. To evaluate the validity of the model analysis, the calculated results are compared with the experimental results in MAG welding. Good correspondence is demonstrated between experiment and calculation. Accordingly, it is concluded that the model is capable of predicting MAG arc welding process.
A Mathematical Modeling of MAG Welding TSUJI, Yoko; YAMAMOTO, Takeshi; MIYASAKA, Fumikazu ...
QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY,
2000, Volume:
18, Issue:
4
Journal Article
Open access
In the present work, a three-dimensional numerical model for MAG (Metal Active Gas) welding of thin plate is developed. In MAG welding, metal is deposited into the molten pool from the electrode ...wire, and the metal plays an important role in determining weld bead profiles. In the model, the thermal energy enters the plates through two mechanisms, i.e., direct heating from arc plasma and indirect heating by melting wire. The transient temperature distribution on base metal is numerically analyzed in order to estimate the molten pool size by using a finite difference model based on heat flow equation, and the theoretical configuration of molten pool is calculated, taking account of the balance of gravity, surface tension and arc pressure. By using these models, the transient MAG welding process is numerically analyzed. The numerical results are in good agreement with the experimental results for bead-on-plate-MAG welds on mild steel plate. Accordingly, it is concluded that the model, proposed in the present work, is useful for prediction of MAG weld bead formations.
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