aluminium in commercial vehicles - European Aluminium Association

More documents

Recommendations

Info

114 EUROPEAN ALUMINIUM ASSOCIATION ALUMINIUM IN COMMERCIAL VEHICLES CHAPTER VIII 3.4. Pulsed current MIG welding An improvement of the MIG process has been achieved by superimposing a pulsed current over the main current, the object being to maintain a low average current level without sacrificing arc stability. The filler metal is transferred to the weld pool every time the current is high (i.e. one drop of metal per pulse). The "cold times" when the current is low ensure that arc stability is maintained. There are three operating modes: • synergetic mode: only the rate of uncoiling has to be regulated. The voltage and frequency are regulated by electronic logic circuits; • manual mode: all the welding parameters are adjustable; • programme mode: each parameter can be stored for use according to production requirements. The pulsed MIG process is limited to thin products of 2 < t ≤ 5 mm and to vertical fillet welds. This process makes it possible to weld thin gauge material with standard filler wire. As the weld pool can be better controlled, butt welds up to 5 mm thickness can be executed without backing bar. Furthermore it is very helpful for welding in the vertical and the over head position. The optimal machine setting is more demanding than for standard MIG because there are much more parameters to be defined. The width of the heat affected zone is analogue to the one for standard MIG as is also the amount of distortion of the work pieces. For welding over stitches see remark under 3.3 above. 3.5. Wire pulsation For gauges between 1 and 3 mm, a complementary option “the wire pulsation” could be added to Welding of a truck door the previously described “current pulsation” in order to improve the arc stability. This “wire pulsation” induces a double pulsation to current signal and consequently to the heat input. For T-joint of dissimilar gauges, the heat input distribution is difficult to maintain constant with classical pulsed current. This double pulsation of current insures the concentration of heat input at the exact location of the joint. 3.6. CMT – Cold Metal Transfer For MIG welding gauges lower than 1 mm, the CMT process (Cold Metal Transfer) could be used. When detecting a shortcircuit, this process retracts the wire so as to help detach the droplet. The thermal input is immediatly reduced and the short-circuit current is kept small.
EUROPEAN ALUMINIUM ASSOCIATION ALUMINIUM IN COMMERCIAL VEHICLES CHAPTER VIII 115 3.7. Edge preparation for MIG welding Just the most frequent examples are given in the Table VIII.1 TABLE VIII.1 EDGE PREPARATION Process Welding Weld Thickness Preparation Remarks position bead TIG All positions One side only 0.8 < t
Page 1 and 2:
ALUMINIUM IN COMMERCIAL VEHICLES
Page 3 and 4:
Aluminium in Commercial Vehicles ha
Page 5 and 6:
VII. FABRICATION . . . . . . . . .
Page 7 and 8:
CHAPTER II ALUMINIUM IN TRANSPORT 1
Page 9 and 10:
EUROPEAN ALUMINIUM ASSOCIATION ALUM
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
CHAPTER III WHY USING ALUMINIUM 1.
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
CHAPTER IV FREQUENTLY ASKED QUESTIO
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
CHAPTER V ALUMINIUM ALLOYS FOR COMM
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
CHAPTER VI DESIGN AND CALCULATION 1
Page 59 and 60:
Page 61 and 62:
Page 63 and 64: EUROPEAN ALUMINIUM ASSOCIATION ALUM
Page 91 and 92: CHAPTER VII FABRICATION 1. INTRODUC
Page 107 and 108: CHAPTER VIII WELDING 1. FOREWORD .
Page 113: EUROPEAN ALUMINIUM ASSOCIATION ALUM
Page 129 and 130: CHAPTER IX OTHER JOINING TECHNIQUES
Page 137 and 138: CHAPTER X DECORATION AND FINISHING
Page 141 and 142: Cell wall EUROPEAN ALUMINIUM ASSOCI
Page 145 and 146: CHAPTER XI CORROSION RESISTANCE 1.
Page 153 and 154: CHAPTER XII CLEANING OF ALUMINIUM C
Page 157 and 158: CHAPTER XIII REPAIR OF ALUMINIUM CO
show all

aluminium in commercial vehicles - European Aluminium Association

Create successful ePaper yourself

Delete template?

Save as template?