Study on Variable Stress Corrosion Susceptibility of Four Typical High-Strength Sucker Rods in High-Salinity Well Fluids

To study the corrosion characteristics of high-strength sucker rods in high-salinity well fluids under alternating stresses, a single-factor stress test was designed. The slow strain rate tensile (SSRT) carried out for four kinds different Cl− and HCO3− concentrations with service strengths, variable cracking susceptibility analyzed. results show that elongation loss absorbed work H-grade ultra-high-strength 4330 rod after are greater than those both 4142 20CrMoA rod. 30CrMoA less affected by changes HCO3−. With increase use strength, increase. change surface during process is inconsistent actual loss. It can be concluded not necessarily related to strength suitable applications wells high concentration Cl−, but it operation alkaline conditions where corrosive media such as coexist. Under highly mineralized conditions, susceptible corrosion. lower In fluids, higher is. weight-loss-based plastic may contradict determination material working conditions.