PHiLARC - The No. 1 Choice of Welders

PHiLARC Tips

  • EIGHT (8) FACTORS TO CONSIDER IN SELECTING ARC WELDING ELECTRODES

    1. Base Metal Strength Properties

    Know and match mechanical properties. Mild steel-generally E-60XX or E-70XX electrodes match base metal. Low alloy steel-select electrodes that match base metal properties.

     

    2. Base Metal Composition

    Know and match the composition. Mild steel-any E-60XX or E-70XX electrode is satisfactory. Low alloy steel-select electrode that most closely matches base metal composition.

     

    3. Welding Position

    Match electrode to welding position encountered.

     

    4. Welding Current

    Match power supply available. Some electrodes are designed for direct current (DC); others, alternating current (AC); some, either. Observe correct polarity.

     

    5. Joint Design and Fit Up

    Select for penetration characteristics – digging, medium, or light. No beveling or tight fit up – use digging. Thin material or wide root opening-light, soft arc.

     

    6. Thickness and shape of base metal

    To avoid weld cracking on thick and heavy material of complicated design, select electrode with maximum ductility. Low hydrogen processes or electrodes are recommended.

     

    7. Service condition and/or specifications

    Determine service conditions – low temperature, high temperature, shock loading-match base metal composition, ductility and impact resistance. Use low hydrogen process. Also check welding procedure or specification for electrode type.

     

    8. Production efficiency and job conditions

    For high deposition and most efficient production under flat position requirements, select high iron powder types or large diameter wires: For other conditions, you may need to experiment with various electrodes and sizes.

  • PRACTICAL TIPS FOR WELDING ALUMINUM

    1) For heat treated alloys:
    -select the alloy that will be least affected by the weld thermal cycle.
    -design assemblies so that weld joints are located in places less subject to stress
    -use as short a weld cycle as possible

    2) Aluminum - copper alloys (2XXX series) are highly susceptible to burn through. To minimize the risks, pass through the solidification range quickly.

    3) If the base metal temperature exceeds 350ºC, recrystallization of the cold worked zone occurs causing a lowering of mechanical strength.

    4) When welding, annealing may occur, thereby undoing all the effects of previous heat treatments.

    5) Tendency to hot cracking is greater when the weld metal contains from 0.5 to 1.5% silicon and/or 0.5 to 2.5% magnesium.

    6) Aluminum – magnesium alloys (6XXX series) have the highest resistance to atmospheric corrosion. However, that are anodic with respect to several non-heat-treated alloys and can corrode when welded to the latter.

    7) Using filler metal containing silicon (4043) when welding an alloy of a type other than aluminum – silicon produces blackening of the weld during the post weld anodizing treatment.

    8) Careful joint preparation ensures good penetration and strong mechanical properties (see OPERATIONAL WELDABILITY, page )

    9) In order to retain heat, when brazing or arc-welding Aluminum, put fire bricks or asbestos sheets under the work piece.

    10) Preheat large sections uniformly. The temperature of acetylene-oxygen flame reaches the range of 5700ºF even if the flame adjustment is reducing (excess acetylene). The melting point of aluminum us only 1220ºF.

    11) Keep work piece at pre-heat temperature during the welding or brazing process.

    12) Remove flux residues after welding or brazing by means of brushing with warm water or flux removing solutions.

    13) When arc-welding aluminum it is well to remember that the melt-off rate of the electrode, due to the tremendous temperature of the arc (4000ºC) and low melting temperature of the aluminum core wire (650ºC) is exceptionally high. To achieve an even arc-length it is important therefore to feed the electrode rapidly.

    14) When brazing aluminum take into account that the oxide-film which forms and covers aluminum instantly, melts at 1650ºC. The underlying aluminum melts much sooner at 660ºC. A chemical (flux 4) is used to dissolve the high melting oxides and to prevent formation of new oxides during the brazing operation.

  • HARD TIME WITH PRE-HEATING AND CRACKING?

    Have you ever encountered cracking on your weld and even on your base metal after welding? Do you feel that it is so difficult to follow the highly technical pre-heat, post heat and inter-pass temperatures needed to achieve the perfect weld?

    PHILARC introduces PHILARC SUPER-ALL AROUND WELD!

    PHILARC SUPER-ALL AROUND WELD:

    Can weld dissimilar metals of all sorts (Stainless Steel, High Nickel Alloys, Steel)

    High tensile strength of up to 570 N/mm2

    High Heat service of over 1150°C (2180°F)

    Tough but machinable

    For use with unknown base metals

    For use with dissimilar metals

    For low temperature steels

    Non-contaminating to food

    Corrosion resistance as well

    No more re-work! Savings on manpower, time and energy! Get the work done within your time table and satisfy your needs or your customer’s needs.