Due to the cold climate and environmental requirementsof Alaska’sNorth Slope and Western Canada’soil production areas, linepipe steels intend for use in these areas, must display not only high strengthas required, but superior toughness. Additionally, if the linepipe is to be used in aggressive sour gas (i.e. H2S containing )environments it must also have excellent resistance to hydrogen induced cracking (HIC). Such a steel has been designed, through selective chemistry, clean steel-making practices, nonmetallic inclusion control, and hot mill pro ces process control, that is capable of meeting stringent line pipe specifications covering X65 grade line pipe in Arctic service temperatures. This paper also examined the effect that hot rolling finishi ngtem finishing temperature had on notch toughness.
Steel-making knowledge developed for lower strength, HIC resistant X52 grade steel has been employed for the development of a X65 grade steel. Resultsof trial heats will be presented. Keywords: high-frequency
resistance welded pipe, low temperature, notch toughness, hydrogen
induced cracking, steel-making, hot rolling finishing temperature