Wednesday, November 4, 2015

Radiograph and IP (off The Facebook)

James H
I recently had a friends weld get rejected by xray for a concave bead.  Repaired it, reshot it, and it came back rejected for IP.  Two times in this last year I've heard this. Both times, same example. Is it just a bad xray tech or is it a change in the rules today?

Paul W Cameron - CWI
A friend eh?
Let me preface this by saying, "I'm no RT Guy." but, a concave bead in a radiograph could easily mask Incomplete Joint Penetration (IP).
A concave bead will appear darker (because it's thinner) than the base material around it when viewed in a radiograph. Once that concave bead is repaired (adding more weld [making it thicker then base material]) the area that was once dark is now light and any IP would be clearly visible.

Great Question!

WPS from Multiple PQRs?

Hey Paul,
How does one support a WPS from multiple PQR's?

I've used multiple PQR's on a single WPS many, many, many times.  When creating a WPS in manufacturing for GMAW I may want the WPS to cover all the electrode diameters (0.035, 0.045, 0.052) and wire feed speed (WFS) ranges that can be run.  A typical ER70S-6 WPS could take me 9 PQRs (3 dial. x 3 WFS ranges).  That was common for me as a Welding Engineer.
When I qualify a single PQR I'll write as many WPS's from it as I can.  Example: I qualify a Bevel Groove with a PQR, I'll also write a WPS for a V-Groove, a U- or J-, all the PJP's I can and Fillets.  I try to get as much “Bang For My Buck” as I can.