• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.6
• /
• pp.20-28
• /
• 2003

This paper presents development of a high speed rotating arc sensor system using a microprocessor based controller with tracking function for a complicate curved fillet welding line, The welding tip connected to the torch body is eccentrically positioned from the centerline of the torch, The area during one rotating cycle is divided into 4 regions of front, rear, right and left in welding direction of the torch tip to determine the horizontal deviation between the welding seam and the torch position. The average value at each region is calculated using the regional current values and a low pass filter incorporated with the moving average method is implemented. The effectiveness of the developed system is proven through the experimental results for several kinds of complicate curved fillet welding lines.

• International Journal of Korean Welding Society
• /
• v.3 no.2
• /
• pp.46-52
• /
• 2003

The refinement of microstructure and phase transformation near the interface of pure copper/carbon steel dissimilar metals joints with various friction welding parameters have been studied in this paper. The microstructure of copper and carbon steel joints were changed to be a finer grain compared to those of the base metals due to the frictional heat and plastic deformation. The microstructure of copper side experienced wide range of deformed region from the weld interface and divided into very fine equaxied grains and elongated grains. Especially, the microstructures near the interface on carbon steel were transformed from ferrite and pearlite dual structure to fine ferrite, grain boundary pearlite and martensite due to the welding thermal cycle and rapid cooling rate after welding. These microstructures were varied with each friction welding parameters. The recrystallization on copper side is reason for softening in copper side and martensite transformation could explain the remarkable hardening region in carbon steel side.

• Journal of Welding and Joining
• /
• v.12 no.1
• /
• pp.73-79
• /
• 1994

Low cycle fatigue test was performed by companion specimens method to compare the properties of cyclic strain for the weldments of controlled rolling steel CR60 and welding structural steel SM58Q. And the result does not showed any difference of low cycle fatigue life between weldments. Especially, the values of coefficient of cyclic plastic strain $C_{p}$ and exponent of cyclic plastic strain $K_{p}$ of heat affected zones of CR60 steel and SM58Q steel were same. And $C_{p}$ and $K_{p}$ of CR60 steel were equal to the values of weld it means a good combination between the base metal, the heat affected zone and the weld of CR60 steel.eel.eel.

• Journal of Welding and Joining
• /
• v.32 no.4
• /
• pp.1-9
• /
• 2014

A quantitative understanding on the effect of the welding conditions on weld joint dimensions and weld thermal cycle is difficult through experimental studies alone. The experimental realization of temperature distribution in the weld pool is proved to be extremely difficult due to the small size of welds, high peak temperature and steep temperature gradients in weld pool. This review deals with the heat transfer and fluid flow analysis to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the weld bead dimensions, temperature and fluid flow distribution in the weldment.

• Journal of Welding and Joining
• /
• v.14 no.3
• /
• pp.41-47
• /
• 1996

The spot weldability of coated steels for automobile has been investigated. Coated steels of SPC-Zn DC, SPC Zn-Ni SC, SPC Zn-Ni DC, SPC Zn-Fe DC and OCCS were welded under different conditions of welding current, force and time. Coating thickness at the welded surface was reduced as increased welding current. Tensile shear strength(TSS) and cross tensile strength (CTS) were increased up to expulsion began, then dropped as increased current. Optimum conditions of welding force and time were different, however 200~250kgf and 15~20cycle were optimum for coated SPC (Steel Plate Cold). Weldability lobes were measured for each coated steel and they showed narrow range of working welding current. The organic composite coated steel (OCCS) had the highest current to get $\sqrt5{t}$ nugget size and narrowest working welding current range.

• Journal of Welding and Joining
• /
• v.24 no.5
• /
• pp.1-6
• /
• 2006

• Proceedings of the KWS Conference
• /
• 2007.11a
• /
• pp.63-66
• /
• 2007

• Proceedings of the KWS Conference
• /
• 2001.05a
• /
• pp.210-213
• /
• 2001

• Proceedings of the KWS Conference
• /
• 2005.06a
• /
• pp.305-307
• /
• 2005

• Journal of Welding and Joining
• /
• v.19 no.1
• /
• pp.82-87
• /
• 2001

The creep-rupture and low cycle fatigue properties of transient liquid phase bonded joints of Ni-base single crystal superalloy, CMSX-2 was investigated using MBF-80 insert metal. The (100) orientation of bonded specimen was aligned perpendicular to the joint interface. CMSX-2 was bonded at 1523K for 1.8ks in vacuum, optimum bonding condition. The creep rupture strength and rupture lives of the joints were the almost identical to ones of the base metal. SEM observation of the fracture surfaces of joints after creep rupture test revealed that the fracture surfaces classified three types of region, ductile fracture surface, cleavage fracture surface and interfacial fracture surface. The low cycle fatigue properties of the joints were also the same level as those of base metal. The elongation and reduction of area values of joints were comparable to those of base metal while fell down on creep rupture condition of high temperature.