What are the factors affecting HIC performance in pipeline steel?Seamless line pipe is mainly used to transport high pressure oil and gas near the wellhead. With the increasing problem of hydrogen sulfide corrosion, the development of sulfur-resistant seamless line pipe is imminent, and the performance of sulfur resistance is the key.
With the deepening of oil and gas exploitation, the mining conditions are complex and there are more and more oil and gas wells in the sulfur-containing environment, and the problem of hydrogen sulfide corrosion is very sharp. In recent years, the demand for anti-sulfur seamless line pipes at home and abroad has been increasing. The seamless line pipe is mainly used for conveying high-pressure oil and gas near the wellhead. It is a steel pipe without weld seam manufactured by seamless pipe production. This paper discusses the factors affecting HIC performance in the anti-sulfur seamless line pipe.
Factors affecting HIC performance
1 Media factors
1) pH value. A large number of studies have shown that the sensitivity of hydrogen bubbling decreases with increasing pH in the range of pH 1-6. When pH>6, hydrogen bubbling does not occur.
2) H2S concentration. The higher the concentration of hydrogen sulfide, the greater the sensitivity of hydrogen bubbling.
3) Chloride ion. In the range of pH 3.5 to 4.5, the presence of Cl- increases the corrosion rate and increases the sensitivity of hydrogen bubbling.
4) Temperature. At 25 degrees Celsius, the CLR is the largest and hydrogen bubbling is the most sensitive. Below 25 degrees Celsius, the temperature rise causes the corrosion reaction and hydrogen diffusion rate to increase, and the sensitivity of hydrogen bubbling increases. Above 25 degrees Celsius, the sensitivity of hydrogen bubbling is reduced due to the decrease in H2S concentration.
5) Time. The test used 96 h as a comparison. Under normal circumstances, the corrosion degree tends to increase with the increase of test time.