Carbon seamless steel pipe is mainly used to transport high pressure oil and gas near wellhead. With the increasingly serious corrosion problem of hydrogen sulfide, the development of seamless pipeline with sulfur resistance is imminent, and sulfur resistance is the key. The effects of Cu and Ni on HIC properties and S content of seamless pipe material were studied. The effects of adding Cu and Ni on the properties of HIC were also studied. Hydrogen bubbling sensitivity.


1. Testing methods
According to ISO3183 standard, ingot casting method is used to smelt 7T 1 ton ingot in laboratory. After forging, piercing, pipe jacking and sheet reduction, the pipe is cut into 20 mm * 100 mm * 5 mm, and then immersed in the solution prepared according to the standard. After 96 hours, the samples were taken out perpendicular to the cross section. Three parameters (crack length ratio CLR, crack thickness CTR and crack sensitivity CSR) are calculated by metallographic method. (HIC) susceptibility.


2. Factors affecting HIC performance
1) PH. A large number of studies have shown that the sensitivity of hydrogen bubbling decreases with the increase of pH value, ranging from 1 to 6. When pH > 6, hydrogen bubbles do not occur.
2) H2S concentration. The higher the concentration of hydrogen sulfide, the higher the sensitivity of hydrogen bubbling.
3) chloride ion. The presence of Cl-increases the corrosion rate and the sensitivity of hydrogen bubbling in the range of 3.5 to 4.5 pH.
4) Temperature. CLR is the largest and hydrogen bubbles are the most sensitive at 25 C. The corrosion reaction and hydrogen diffusion rate increase and the sensitivity of hydrogen bubbling increases when the temperature is lower than 25 C. The concentration of H2S decreases but the sensitivity of hydrogen bubbling decreases after 25 C.
5) Time. Using 96 h as contrast, the corrosion degree becomes serious with the increase of test time under normal conditions.