This document specifies methods for testing the corrosion performance of corrosion resistant steels and their welded joints for use in crude oil tankers cargo tanks, including sampling and specimen preparation, test equipment, test conditions, procedures, evaluation of results, and reporting requirements. The scope of application includes corrosion resistant steels for use in crude oil tankers cargo tanks and their welded joints, which involve upper deck corrosion steel, inner baseplate corrosion resistant steel, and welded joints. The document refers to a series of normative documents, which specify the necessary terms and definitions. The Overview section describes the complex corrosion environment unique to crude oil tankers cargo tanks, emphasizing the severity of corrosion on the upper deck and lower surfaces due to the dry and wet cycle state.