Suitability of Various Tubeplate Materials for Use with Thin Walled Laser Welded UNS S34565 Stainless Steel Tubing in MSF Desalination Plant Evaporators

摘要

Previous studies, in sea water containing oxygen levels of 65,150 and 750ppb at 90 deg C, have shown the suitability of thin walled, laser welded UNS S34565 stainless steel tubing for MSF desalination plant evaporators. However, in the tests carried out, some galvanic corrosion was observed on UNS S32760 super duplex stainless steel tubeplate material. Further work has been carried out to study the use of UNS S31603 and S34565 as tubeplate material in these environments. Results show welded tube-tubeplate assemblies to be suitable with all materials tested; with rolled tube-tubeplate joints slight corrosion was observed, the extent being a function of the oxygen level.