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Use of a new 16% moly alloy for weld surfacing in sour environments

Conference ·
OSTI ID:70055
;  [1]; ;  [2]
  1. FMC Corp., Houston, TX (United States)
  2. Krupp-VDM GmbH, Houston, TX (United States)

Special low iron Ni-Cr-Mo alloy 625 as a weld overlay material on low alloy steel for well head applications has been successfully used and continues to be used in the sour corrosive environments of the oil/gas industry. The presence of high chlorides, carbon dioxide and hydrogen sulfide combined with high pressures and temperatures necessitated the use of an alloy with a Pitting Resisting Equivalent as defined by PRE = % Cr + 3.3 {times} % (Mo) of at least 50 or greater. However, in certain sour environments and higher temperatures, alloy 625 reaches its limits and failures have been reported from the field. Another alternative for significantly extending the window of operation and provide better reliability and versatility is offered by a new high chromium, high molybdenum and a very high PRE alloy of the Ni-Cr-Mo family, known as alloy 59 (UNS N06059). This paper presents the initial test results of a preliminary research program conducted on alloy 59 as a better weld overlay material.

OSTI ID:
70055
Report Number(s):
CONF-940222--
Country of Publication:
United States
Language:
English