1 / 13

Zinc

Zinc. Resistance Welding . Learning Activities View Slides; Read Notes, Listen to lecture Do on-line workbook. Lesson Objectives When you finish this lesson you will understand:. Keywords. Zinc Specific Gravity 7.14, slightly less than iron Low melting temp 787F (419C)

heller
Download Presentation

Zinc

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Zinc

  2. Resistance Welding • Learning Activities • View Slides; • Read Notes, • Listen to lecture • Do on-line workbook • Lesson Objectives • When you finish this lesson you will understand: Keywords

  3. Zinc • Specific Gravity 7.14, slightly less than iron • Low melting temp 787F (419C) • Low boiling temp 1665F (907C) - Fuming, Vapor • Electrical Conductivity 25% of Copper (2 x steel) • Zinc Alloys • Two Alloy Types • Cast Zinc • Rolled Zinc • Zinc Alloys Brittle at RT, elevated temp mechanical working • Zinc Alloys have recrystallization temp at or below RT • Recrystallization reduces strength in rolled alloys • Use low heat input to reduce HAZ Softening (Resistance Weld) • Mechanical Clean & Abraded to clean surface

  4. Uses • Cast forms • Roofing • Chemical Processing Applications

  5. Resistance Welding of Rolled Alloys • Spot & Seam Welding • Equivalent or Slightly Lower Current than steel (lower resistance, lower melting temp) • Lower Force than steel (softer) • Low inertia head, more indentation needs faster follow-up • Disp Strengthened Electrodes, High alloying with copper • Mechanical clean surface • Internal defects or cavities common, low boiling point • Forge force can help • Seam Welding • Increased roll speed requires increased current

  6. Cu Zn

  7. Rolled Alloy Spot & Seam

  8. Cast Alloy Spot & Seam Weld

  9. Electrode: class 2 with 3 in radius dome

  10. Electrode: class 2 with 15 degree bevel and face radius of 3 inches

  11. Resistance Welding of Cast Zinc Alloys • Start with the same recommendation as Rolled Alloys • High Resistance Films (electro-deposited & others) Removed The castings generally have extra coatings

More Related