Abstract
Corrosion sensitivity of the CW625 brass alloy during exposition to the sea water
(field test) and to drinking water (rig test with cooled water circle), over a time
span of six and two years respectively, has been evaluated. Forged and machined
couplings were selected to be exposed to the sea water while tubes manufactured through an extrusion/machining processing route were applied in the rig test. Evaluation is based on a systematic measuring of the depth of corrosion observed in the test articles. The tests have revealed dezincification as the dominating corrosion form in couplings, but intergranular corrosion (IGC) was a main corrosion form in the tubes. To understand the mechanism behind the IGC observed in the beta annealed alloy, a systematic investigation of the corrosion products and chemistry that occurred along the grain boundaries has been performed by scanning/transmission electron microscopes (STEM).
(field test) and to drinking water (rig test with cooled water circle), over a time
span of six and two years respectively, has been evaluated. Forged and machined
couplings were selected to be exposed to the sea water while tubes manufactured through an extrusion/machining processing route were applied in the rig test. Evaluation is based on a systematic measuring of the depth of corrosion observed in the test articles. The tests have revealed dezincification as the dominating corrosion form in couplings, but intergranular corrosion (IGC) was a main corrosion form in the tubes. To understand the mechanism behind the IGC observed in the beta annealed alloy, a systematic investigation of the corrosion products and chemistry that occurred along the grain boundaries has been performed by scanning/transmission electron microscopes (STEM).