Seamless steel pipe with excellent hydrogen sulfide stress corrosion resistance and manufacture method thereof

Abstract

The invention discloses a seamless steel pipe with excellent hydrogen sulfide stress corrosion resistance and manufacture method thereof, wherein chemical components, by weight percentage, are: 0.19% to 0.24% of C, not more than 0.30% of Si, 0.20% to 0.50% of Mn, 0.90% to 1.30% of Cr, 0.60% to 0.80% of Mo, 0.10% to 0.15 % of V, 0.01% to 0.15% of Ti, not more than 0.012% of P, not more than 0.005% of S, not more than 0.00015% of H, not more than 0.0050% of N, not more than 0.0040% of O, not more than 0.0080% of total As, Sn, Pb, Sb and Bi, 0.0010 to 0.0030 of Ca, and the balance being Fe and trace impurities. The manufacture method of the seamless steel pipe is three-step heat treatment, comprising: step 1, an austenization treatment for a hot rolling steel pipe under 950 - 970 DEG C, and then discharging and quenching to below 200 DEG C; step 2, a secondary insulation for the first quenched steel pipe under 880 to 920 DEG C and quenching to below 200 DEG C, and then a tempering treatment under 690 to 730 DEG C for 60 to 150 minutes; step 3, a straightening treatment with a temperature which is not less than 300 DEG C and a destressing treatment under 650 to 680 DEG C for the quenched and tempered steel pipe.

Description

technical field [0001] The invention belongs to the field of low-alloy steel manufacturing, and in particular relates to a hydrogen sulfide stress-corrosion-resistant low-alloy seamless steel pipe with a yield strength of 110ksi (758MPa) and a heat treatment method thereof. Background technique [0002] The problem of hydrogen sulfide stress corrosion of oil well pipes is a major issue faced by many oil fields at home and abroad in recent years. From the perspective of oil well pipe materials, ordinary API oil well pipes obviously cannot meet the actual use requirements, especially in Sichuan oilfields and In some areas of oilfields such as Changqing and Tarim, as well as some oilfields in the United States and Canada, oil well pipes are required to have high hydrogen sulfide stress corrosion resistance. [0003] Today, the huge daily consumption of oil and natural gas forces the drilling depth of oil fields to increase continuously, and the use environment of oil well pipes...

AI Technical Summary

Problems solved by technology

Hardness, steel pipe residual stress value, and microstructure grain size are not reported in the prior art, and only two patents with application numbers CN200610016498.6 and CN200810238135.6 discuss the influence of steel pipe hardness on SCC resistance, but their 100 The HRC hardness value of -110ksi grade steel pipe cannot be controlled below 27HRC, and the stability of SSC resistance performance is difficult to guarantee

Images