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Title: Investigation of a Modified 9Cr-1Mo (P91) Pipe Failure

Abstract

A modified 9Cr-1Mo feedwater (condensate) line at an Eastman Chemical Company plant failed in January 2005. The line was in continuous service since start-up December 2001 until failure. The Plant Superintendent estimated there were three thermal cycles since start-up, although there may have been as many as 25 thermal cycles during commissioning. Normal operating temperature was 325 F (163 C) and pressure was 1762 psig. The line was steam traced with the tracing activated only when ambient outdoor temperature dropped to 40 F (5 C). A modified 9Cr-1Mo steel (P91) pipe failure in a feedwater line in a chemical plant was investigated. The failure occurred in the vicinity of an elbow produced with socket welds of the pipe to the elbow. Based on metallography and hardness measurements, it was concluded that failure occurred because of an improper post-weld heat treatment of the socket weldment.

Authors:
 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shared Research Equipment Collaborative Research Center
Sponsoring Org.:
FE USDOE - Office of Fossil Energy (FE)
OSTI Identifier:
974591
Report Number(s):
ORNL/TM-2006/001
AA1510100; FEAA028; TRN: US201008%%488
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHEMICAL PLANTS; COMMISSIONING; FEEDWATER; HARDNESS; HEAT TREATMENTS; METALLOGRAPHY; OUTDOORS; START-UP; STEAM; STEELS

Citation Formats

Klueh, Ronald L, and Shingledecker, John P. Investigation of a Modified 9Cr-1Mo (P91) Pipe Failure. United States: N. p., 2006. Web. doi:10.2172/974591.
Klueh, Ronald L, & Shingledecker, John P. Investigation of a Modified 9Cr-1Mo (P91) Pipe Failure. United States. doi:10.2172/974591.
Klueh, Ronald L, and Shingledecker, John P. Sat . "Investigation of a Modified 9Cr-1Mo (P91) Pipe Failure". United States. doi:10.2172/974591. https://www.osti.gov/servlets/purl/974591.
@article{osti_974591,
title = {Investigation of a Modified 9Cr-1Mo (P91) Pipe Failure},
author = {Klueh, Ronald L and Shingledecker, John P},
abstractNote = {A modified 9Cr-1Mo feedwater (condensate) line at an Eastman Chemical Company plant failed in January 2005. The line was in continuous service since start-up December 2001 until failure. The Plant Superintendent estimated there were three thermal cycles since start-up, although there may have been as many as 25 thermal cycles during commissioning. Normal operating temperature was 325 F (163 C) and pressure was 1762 psig. The line was steam traced with the tracing activated only when ambient outdoor temperature dropped to 40 F (5 C). A modified 9Cr-1Mo steel (P91) pipe failure in a feedwater line in a chemical plant was investigated. The failure occurred in the vicinity of an elbow produced with socket welds of the pipe to the elbow. Based on metallography and hardness measurements, it was concluded that failure occurred because of an improper post-weld heat treatment of the socket weldment.},
doi = {10.2172/974591},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Apr 01 00:00:00 EST 2006},
month = {Sat Apr 01 00:00:00 EST 2006}
}

Technical Report:

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