P33 to P1 Repair weld??
P33 to P1 Repair weld??
(OP)
We have a heat exchanger that has started to leak due to a crack/ separation of the tube header plate to the shell. This is causing a contamination of the lake water that is used to cool the Cooling water.
The plate is P33 (silicon bronze) and the shell is P1. It has been welded before (made in the 1950's) and the original weld has cracked in the HAZ on the carbon steel side.
We have tried to contact the manufacture of this but they have been sold out and moved so many times that the original WPS can't be found.
We have tried several times to create our own PQR/WPS for the repair, however it always breaks in the HAZ on the bronze side and we have been unable to qualify this procedure.
Any help??
The plate is P33 (silicon bronze) and the shell is P1. It has been welded before (made in the 1950's) and the original weld has cracked in the HAZ on the carbon steel side.
We have tried to contact the manufacture of this but they have been sold out and moved so many times that the original WPS can't be found.
We have tried several times to create our own PQR/WPS for the repair, however it always breaks in the HAZ on the bronze side and we have been unable to qualify this procedure.
Any help??





RE: P33 to P1 Repair weld??
RE: P33 to P1 Repair weld??
HAZ cracking is usually not a problem with brazing.
More details please.
RE: P33 to P1 Repair weld??
ERCuAl-A2 filler metals.
RE: P33 to P1 Repair weld??
RE: P33 to P1 Repair weld??
GMAW, ERCuAI-A2, .035 DCEN, AMPS145-195, VOLTS 23-25
They are testing it as a double bevel weld. I think the bend test will never work because of the dissimilar metals. Is it possible to test it as a fillet weld (as that is what the joint to be repaired is) and do a micro or macro etch test rather than bending?
RE: P33 to P1 Repair weld??
RE: P33 to P1 Repair weld??
Also found out that when they preheated the test to 325 it would break on the bronze side and then when welded with no preheat it would break on the P1 side either way it was in the HAZ.
RE: P33 to P1 Repair weld??
ASME Section IX
QW-161.5 Longitudinal-Bend Tests. Longitudinal bend
tests may be used in lieu of the transverse side-bend,
face-bend, and root-bend tests for testing weld metal or
base metal combinations, which differ markedly in bending
properties between
(a) the two base metals, or
(b) the weld metal and the base metal
RE: P33 to P1 Repair weld??
Scroll down to
Materials with 3% to less than 20% elongation
Dimensions are provide for the plunger radius and shoulder distance.
RE: P33 to P1 Repair weld??
Preheating the Al Bronze causes more heat to flow to the lower-conductivity metal during welding (because of the larger temperature difference) and thus leads to a more even heating of the weld assembly. Heating the higher-conductivity base metal also reduces the cooling rate after welding, and this helps reduce post-weld thermal stresses.
The balance of heat is important in these joints.
I would also recommend GMAW or GTAW w/ GMAW fill.