Reducing Helium Use for GMAW on Nickel Based Alloys - QuickView

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Reducing Helium Use for GMAW on Nickel Based Alloys - QuickView

  1. 1. QuickViewQuickView Reducing the use of Helium in GMAW Applications on Nickel-Based Alloys Improve Productivity & Quality; Reduce Total Cost MATHESON QuickView Application Review and Summary
  2. 2. QuickViewQuickView Helium Supply Update • Helium is a non-renewable resource • Helium supply is subject to variability – Helium prices fluctuate … and the future is unpredictable • For welding applications, alternatives to helium exist – Many of the alternatives offer advantages Now is the time to consider shielding gas alternatives that use less - or zero - helium.
  3. 3. QuickViewQuickView Why use Helium? • Helium creates a high energy arc – High ionization potential (24.5874 eV) – Produces hotter arc (at higher voltages) • Produces a shallower, wider bead profile – Effect is proportional to Helium concentration • High heat can be advantageous on thicker sections • Helium can be useful on aluminum, magnesium, copper alloys • Helium when blended with Argon, CO2, and other gases, creates a mixture with blended characteristics Frequently Specified Application: Mixtures rich in Helium – typically 90% - for Stainless Steel
  4. 4. QuickViewQuickView Helium’s Disadvantages • Helium’s high ionization potential leads to: – Less stable arc – can lead to inconsistent results Disadvantages are proportional – Hotter arc – can lead to distortion & warping to Helium concentration • Helium can lead to penetration issues • Helium can increase spatter • Helium is a light atom and a less effective shield – Helium flow rate per unit of deposited metal is higher than other gases • Helium is subject to supply and price variability – The cost of Helium must be considered in high production applications Using more He is not the only choice; and is often not the best choice.
  5. 5. QuickViewQuickView GOAL: Reduce or Eliminate Helium Use • Alternatives to Helium exist • Helium use can be reduced Consider mixtures or eliminated optimized for the • With excellent results: process and – Better weld penetration application. – Significant reduction in porosity – Increased travel speed – Improved arc stability; less spatter and smoke – Improved puddle and flow control (smaller droplet) – Reduced Heat Affected Zone (HAZ) – Less heat-related damage to base material – Reduced burn-through on thin materials – More flexibility to use other processes (spray and pulsed spray, in addition to short circuit)
  6. 6. QuickViewQuickView GMAW on Nickel-Based Alloys
  7. 7. QuickViewQuickView Nickel-Based Alloys GMAW • Outdated: 90%He / 7.5%Ar / 2.5%CO2 – Expensive for GMAW of stainless steel and other alloys due to high concentration of Helium – Narrow voltage range (18V-22V) – Limited to Short Circuit Transfer – High heat (due to high ionization potential of He) is detrimental to mechanical properties of base material – Distortion, poor color match, warpage, suck-back, poor productivity
  8. 8. QuickViewQuickView Nickel-Based Alloys GMAW • Different conventional setups for stainless steels – For Short Circuit: 90%He / 7.5%Ar / 2.5%CO2 – For Normal or Pulsed Spray: 98%Ar / 2%O2 • Well known fact: – Neither of the above shielding gas mixtures is optimized for both short circuit and spray • For Stainless Steels, you must have two setups with traditional gas mixture compositions – one for short circuit and one for spray
  9. 9. QuickViewQuickView Nickel-Based Alloys GMAW • 90%He / 7.5%Ar / 2.5%CO2 – Works well for Short Circuit • Here’s why you can’t use it for Spray Arc: 90%He / 7.5%Ar / 2.5%CO2 If used for Spray Arc: • Very unstable arc • Large droplet formation • Explosive transfer
  10. 10. QuickViewQuickView Nickel-Based Alloys GMAW • MATHESON Select® HC-725 (and HC-332) – Use up to 90% less Helium; uses more Argon instead – Expanded Voltage Range (14.5V-38V) • Use of lower voltages results in less heat input – Lower operating temperature Stainless Steel • Inconel® Reduced heat on lighter materials Hastelloy® • Reduced burn through, suck-back Monel® • Reduced HAZ • Reduced hexavalent chromium emission – Higher productivity and lower total welding cost – One mix ideal for short circuit, spray, and pulsed spray
  11. 11. QuickViewQuickView Nickel-Based Alloys GMAW • MATHESON Select® HC-725 – One mix ideal for short circuit, spray, and pulsed spray – One setup is appropriate for all processes • Here’s a look at MATHESON Select® HC-725 for Spray Arc: HC-725 with Spray Arc: • Stable plasma • Small droplet formation • Smooth transfer
  12. 12. QuickViewQuickView Nickel-Based Alloys GMAW • In some applications: – Users may be able to switch from Short Circuit to Spray Arc – Spray Arc is faster – reducing not only time, but cost • Some studies show total cost cut in half! – Users who use MATHESON Select® HC-725 Shielding Gas • Can use Spray or Pulsed Spray for higher speed, cost savings, and better results • Can switch back to Short Circuit as needed
  13. 13. QuickViewQuickView In Review … • Forward thinking leads to better solutions Thank you • Use of less Helium can: for your – Produce better results time! – Improve cost per weld – Enable the use of ONE SETUP for all applications on SS • Easily applied in GMAW and GTAW on Nickel-Based alloys • We are here to support you • Learn more: contact your MATHESON rep or visit one of our stores • Find us fast at: www.MathesonGas.com/contactus.aspx

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