Several inspection techniques were required to determine the root cause of the failure
Incoloy 800 HT tubes in steam service in the convection zone of an ethylene cracking furnace failed after 13 years. Examination of the samples at the weld and 100 mm away from the weld of the failed tube revealed initiation of cracks from the outer surface (OD) by the combined effects of creep and intergranular cracking. Prolonged elevated temperature operations beyond 100,000 hr was responsible for accelerating the creep void formation and cracking. The tubes were recommended to be replaced after ferrite measurement. Shifting the central weld to the outside of the furnace (or use single-length tube) was recommended to reduce the tube failure from the heat affected zone (HAZ).
Introduction
Log in to view this article.
Not Yet A Subscriber? Here are Your Options.
1) Start a FREE TRIAL SUBSCRIPTION and gain access to all articles in the current issue of Hydrocarbon Processing magazine.
2) SUBSCRIBE to Hydrocarbon Processing magazine in print or digital format and gain ACCESS to the current issue as well as to 3 articles from the HP archives per month. $409 for an annual subscription*.
3) Start a FULL ACCESS PLAN SUBSCRIPTION and regain ACCESS to this article, the current issue, all past issues in the HP Archive, the HP Process Handbooks, HP Market Data, and more. $1,995 for an annual subscription. For information about group rates or multi-year terms, contact email Peter Ramsay or call +44 20 3409 2240*.
*Access will be granted the next business day.