Development of the NACE MR-01-75 and NACE TM-01-77 Standards, Part I: Field Observations and Metallurgical Factors

This is Part I of a two-part series intended to narrate the “lost” history leading up to the publication of the first Material Requirement (MR-01-75) standard prepared by NACE (now AMPP) and its subsequent auxiliary standards. Part I covers field observations and describe the metallurgical issues that were being investigated in support of NACE T-1B and 1F committees to develop a sour service materials standard for carbon and low alloy steels. Part II focuses on the rationale behind the use of accelerated laboratory test procedures and their development to differentiate metallurgical behavior in sour environments at near atmospheric pressure. The original sulfide stress cracking test methodologies would later be codified as a Test Method in NACE TM-01-77 (1977). A review of the historical events culminating in NACE MR-01-75 will provide a technical basis for the Rockwell C 22 (HRC 22) hardness limit, information on the 1% Ni restriction, and heat-treatment requirements for carbon and low alloy steels. By recalling the origins of the MR-01-75 standard, these papers will also provide justification for their continued existence when designing modern, oil and gas wells and flowlines. As the oil and gas industry continues to innovate and mature, it is imperative to maintain knowledge of the origins of the NACE MR-01-75 standard and its intended purpose.