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21.5 Chapter Conclusion

David Colameco, M.Ed.

Summary

As a welder your school’s welding program usually starts with you welding low-carbon steels, such as ASTM A-36, because it is used throughout the structural welding industry and it is also relatively easy to weld. Low-carbon steels were part of the ferrous grouping of metals. Within this ferrous grouping of metals in Chapter 20, we discussed stainless steel as requiring cleanliness, proper application of shielding gasses, and the strict adherence to the WPS and manufacturer recommendations.

Non-ferrous metals discussed in this chapter take the need for cleanliness and welding procedures to a whole other level of importance. Non-ferrous metals are more rare, making welding opportunities rare. Most welding on non-ferrous metals is performed using automated processes. This doesn’t mean that manual welding opportunities are not available. Companies in Washington State employ welders to weld on these metals which makes it important to introduce you to them.

Review Questions

  1. What is a casting?
    1. Auditions for a movie’s actors.
    2. A metal fabrication formed by pouring liquid metal into a mold.
    3. A metal fabrication formed by rolling hot metal at the foundry.
    4. Protective insulation applied to a pressure vessel to prevent corrosion.
  2. What is weldability?
    1. The name of the welding test employers give to measure your ability to weld.
    2. The relative measure of ease that a metal can be welded.
    3. The measure of a welder’s greatness.
    4. Weldability is not used in welding.
  3. What does the term in-service refer to?
    1. The location that a weldment is installed.
    2. The amount of volunteer time a welder devotes to their community.
    3. The operating environment a weldment will experience such as temperatures and pressures.
    4. In-service is not a term used for weldments.
  4. Which welding process benefits greatly from an inverter power supply?
    1. SMAW.
    2. GMAW.
    3. GTAW.
    4. FCAW.
  5. Which reactive metal causes severe lung disease if its metal dust is breathed in?
    1. Beryllium.
    2. Titanium.
    3. Zirconium.
    4. None of the Above.
  6. What is a protective oxidation layer?
    1. Oxidation is detrimental, a protective oxidation layer is a myth.
    2. A flaky rust coating that continually reforms as flakes fall off.
    3. A loosely bonded oxide layer that serves as a barrier to further deeper oxidation.
    4. A well bonded oxide layer that serves as a barrier to further deeper oxidation.
  7. What makes aluminum different from welding low carbon steel? Select all that apply.
    1. The oxide layer starts to form almost immediately and must be removed prior to welding.
    2. The base metal does not give off visible light when heated, i.e. “glow”.
    3. Abrasive tools must only be used with aluminum to prevent contamination with other metals.
    4. The thermal conductivity is different leading to more distortion.
  8. What properties of non-ferrous metals make them attractive to traditional ferrous metals? Select all that apply.
    1. Improved thermal properties.
    2. Improved strength-to-weight ratios.
    3. Increased strength.
    4. Improved corrosion resistance.
  9. What industries are reactive metals primarily used in. Select all that apply.
    1. Aerospace.
    2. Ballistic armor plating.
    3. Nuclear.
    4. Reactive metals are not used in industry.
  10. Which welding processes have been used to weld aluminum up until WWII? Select all that apply.
    1. Oxy-fuel welding.
    2. SAW.
    3. GMAW.
    4. GTAW.
  11. Why is SMAW not an approved AWS process for structural aluminum welding? Select all that apply.
    1. SMAW of aluminum is approved by AWS in D1.2 Structural Aluminum.
    2. SMAW of aluminum is prone to porosity.
    3. SMAW of aluminum is prone to flux entrapment that causes internal corrosion.
    4. It will be approved if more welders use SMAW, popularity wins the day.
  12. Why is oxyfuel welding not widely used for welding aluminum? Select all that apply.
    1. The HAZ is larger than arc welding processes leading to lower strength in the weldments.
    2. The flux used absorbs water which leads to corrosion if not completely removed.
    3. Oxyfuel welding of aluminum is a widely used process.
    4. None of the above.
  13. What is unique about the 1000 series of aluminum alloys?
    1. The alloy number can be converted to the density of the alloy.
    2. The alloys are at least 99% pure aluminum with the last two digits in the alloy number representing the hundredths of purity (i.e. 1035 is 99.35% pure aluminum).
    3. The alloy number can be converted to the reflectivity of the alloy.
    4. Nothing is unique about the 1000 series of aluminum alloys.
  14. Which industries are known for using aluminum? Select all that apply.
    1. Automotive and trucking industries.
    2. Aerospace.
    3. Maritime.
    4. None of the above.
  15. Which welding process is used with aluminum in the automotive industry but is not usually taught in an introductory welding program.
    1. GTAW.
    2. GMAW.
    3. FSW.
    4. FCAW.
  16. What steps are important when welding cast aluminum? Select all that apply.
    1. Cleanliness of the part.
    2. Maintaining preheat and interpass temperatures.
    3. Identifying crack lengths and end drilling them to prevent further spread.
    4. None of the above.
  17. If a casting needs to be slow cooled how can you slow its rate of cooling? Select all that apply.
    1. Bury the weldment in sand.
    2. Place the weldment back in an oven that is turned off to use the oven’s insulation to slow the cooling rate.
    3. Use welding blankets.
    4. None of the above.
  18. Which welding processes are automated for critical welds? Select all that apply.
    1. SMAW.
    2. GTAW.
    3. GMAW.
    4. FCAW.
  19. What piece of equipment is used when shielding gas coverage on a weldment is difficult.
    1. Additional Preheat.
    2. Welding chamber or welding glove box.
    3. Additional cleaning.
    4. None of the above.
  20. What in service condition are bicycle frames and vehicles exposed to that helps cracks spread more quickly?
    1. Paint.
    2. Vibration.
    3. Sunlight.
    4. None of the above.

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Introduction to Welding Copyright © by Washington State Board for Community and Technical Colleges is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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