The problem of delayed failure or hydrogen-stress cracking in high strength steel has been well known for many years and has been the subject of considerable research.
Samples of line pipe steel were heat treated to yield strengths in the range of 110,000 to 150,000 psi. These steels were subjected to various tensile stresses while being charged with hydrogen in the laboratory under conditions simulating cathodic protection in the field. Hydrogen-stress cracking occurred at stresses in the range of operating stresses that might be used with these high strength steels. Research is still being conducted to determine whether the laboratory tests would predict the field behavior of these materials if they were to be used at the high strength levels.
