Base material fatigue data for low alloy forged steels used in the subsea industry. Part 1: In air S–N data

Base material fatigue data for low alloy forged steels used in the subsea industry. Part 2: Effect of cathodic protection

“…Part 1 of this paper [16] contains in air fatigue test data for a AISI 8630 M steel, ASTM A182 F22 steel, QT steels and a T95 carbon steel. Fatigue testing of the AISI 8630 M steel in 3.5% NaCl seawater solution with cathodic protection with a potential of À1050 mV Ag/AgCl is (in detail) presented below.…”

“…AISI 8630 M fatigue test specimens for environmental S-N fatigue testing were cut and machined from the same low alloy AISI 8630 M thick wall steel forging that was in air S-N tested in Part 1 of this paper [16] (see Fig. 7 in Part 1).…”

“…The reader is also referred to [15] for further information. The S-N curve for the QT(1) steel in Part 1 [16] of this paper is included in DNVGL-RP-0005 as the HS curve. The QT(1) steel [16] has a yield strength of 515 MPa and a tensile strength of 627 MPa giving a yield to tensile strength ratio of 0.82.…”

“…The QT(1) steel fatigue specimens (see Fig. 6(c) in Part 1 [16]) were tested at 3 stress levels (R ¼ 0:1; 0:3 and 0.4), all with a maximum stress of 500 MPa. The mean in air fatigue life results at these 3 stress levels are included in Table 1.…”

“…20 specimens, all with a geometry identical to the in air specimens (Fig. 6(c) in Part 1 [16]), were tested in seawater with CP with a potential of À1050 mV versus a Ag/AgCl reference electrode using an impressed current system. Five specimens were linked together and tested simultaneously in a horisonal test setup.…”