MECHANISATION AUTOMATION - Esab

Skilled operatorMechanisation can never be successful without thesupervision of an experienced operator. He must set theappropriate welding parameters, recognise when theyneed to be adjusted and control the overall process.This calls for an experienced manual welder with expertknowledge.Selection of cored wiresLight mechanisation of MIG/MAG welding is primarilybased on the use of cored wires. The choice of type ofcored wire depends mainly on the welding position andon the required impact strength.Impact toughness: -20ºC• PB-position welding:metal-cored wire OK Tubrod 14.12 (AWS E70C-6M,EN T 42 2 M M 1 H10).• Vertical welding (PF):all-positional rutile flux-cored wire OK Tubrod 15.14,OK Tubrod15.15, FILARC PZ6113 (AWS E71T-1/ENT 46 2 P M 2 H10).• Horizontal-vertical welding (PC):Either cored wire type.Impact toughness: -40ºC• PB-position welding:metal-cored wire OK Tubrod 14.05 (AWS E70C-G/EN T 42 4 Z M M 2 H10).• Vertical welding (PF):all-positional rutile flux-cored wire OK Tubrod 15.17,PZ6138 (AWS E81T1-Ni1/En T 46 3 1Ni P C 2 H5).• Horizontal-vertical welding (PC):Either cored wire type.Light-mechanisation equipmentESAB equipment for light-mechanisation breaks down intwo categories:carriers on rails:• Railtrac 1000 W (Figure 1).• Railtrac 1000 FW.and small tractors:• Miggytrac 1000 (Figure 2).• Miggytrac 2000.• Miggytrac 3000.Typical applicationsFillet weld, PB position.A typical application for a tractor is performing filletwelds in PB-position. The productivity achieved easilydoubles that of manual welding, see table 1. Metal-coredwire OK Tubrod 14.12 is exploited to its maximum.Figure 1. Railtrac 1000.a-size(mm)Weldingcurrent: DC-(A)Arcvoltage(V)Figure 2. Miggytrac 1000.Weldingspeed(cm/min)3.5 320 32 100 164 330 32 90 175 340 33 65 187 340 34 35 19Wirefeed(m/min)Table 1. Fillet welding in PB-position using metal-cored wireOK Tubrod 14.12-1.2mm.Butt weld, PF position.A typical application for a carriage on rails is verticalwelding (PF), which can be either butt welding or filletwelding. Roots of butt welds can be made with ceramicweld metal support.• Vertical welding (PF).• Plate thickness: 14 mm.• Groove and run sequence: 45° V-joint, root pass,two filler layers.• Weld metal support: Ceramic backing.• All-positional rutile flux-cored wire: PZ6113 – 1.4mm.• Shielding gas: 75%Ar+25%CO 2.• 1st pass: 160-180 A, 22-23 V, 10-12 cm/min.• 2nd pass: 180-190 A, 24-25 V, 16-18 cm/min.• 3rd pass: 210-220 A, 24-25 V, 14-15 cm/min.• Weaving and edge stopping time: Depends on actualgroove width.• Impact toughness (weld metal):• -20ºC: 27, 75, 73 / av. 58 J.• -40ºC: 60, 50, 46 / av. 52 J.8 • Svetsaren no. 1 • 2005