Search
Filters
Close

Comparison of the Life Cycle Cost of Carbon Steel, Duplex Stainless Steels, Super Austenitic, and Nickel-Based Alloys for Crude Unit Overheard Condensers

A refinery in the U.S. Gulf Coast had been using carbon steel tubes in two crude unit overhead condensers that suffered severe corrosion leading to premature failure after just 6 months in service. The metallurgy of the tube bundles was later upgraded to super duplex, UNS S32750, and hyper duplex stainless steel (DSS), S32707, which extended the service life to 12 months and two years, respectively. Failure analysis of the DSS indicated that the corrosion started as under-deposit corrosion. Selective corrosion occurred, where the ferrite phase suffered a preferential corrosion attack. Super Austenitic Alloy 35, UNS N08935, was recommended as an economical alternative to nickel Alloys 625 (UNS N0625 and C-276 (UNS N10276). Material selection and life-cycle cost analysis helped the end user select the super austenitic Alloy as the material of choice for the upgrade. The bundles have been in service for more than two years. This paper evaluates the materials selection process, fabrication cost, and life cycle cost analysis of the different Alloys used in these bundles since the first carbon steel upgrade through the present time.
Product Number: 51324-21175-SG
Author: Karen Picker; Luiza Esteves
Publication Date: 2024
$40.00
$40.00
$40.00