07-10-2016, 04:36 PM
1458269506-6f9extraslides.ppt (Size: 536 KB / Downloads: 6)
Types of Defects Revealed by Radiography
Undersize nugget
Inadequate diameter
Inadequate penetration
Oversize nugget
Excessive diameter
Excessive penetration
Odd and misshapen nuggets
Extent of Alclad inclusion into the nugget
Extrusion of the nugget
Cracking of the nugget
Porosity
Expulsion from faying surfaces
Segregation of eutectic in parent material
Electrode pickup
Size or extent or granular zone
Nugget penetration
Setup Procedures and Suggested Schedules
[Step 1] Insert electrode of proper size and tip contour for the gauge combination. Align electrodes.
[Step 2] Set pressure gage for suggested welding force, and check with an electrode force gauge.
[Step 3] Adjust the control to provide the approximate suggested weld and “postheat time”.
[Step 4] The welding currents shown are approximate and intended to be a guide. The magnitude of the welding current is usually controlled by a heat dial or phase-shift control.
[Step 5] Check the machine for consistency of operation by making and testing twenty single spot tension-shear specimens and five macroscopic examination specimens.