Anti-H2S stress corrosion high pressure resistant forgings and method for manufacturing same

Abstract

Disclosed is a sulfureted hydrogen-proof stress corrosion high pressure-resistant forge piece, comprising the compositions, in weight percent: C: 0.26 to 0.30, Mn: 0.80 to 1.00, Cr: 0.80 to 1.00, Si:0.20 to 0.35, Ni: 0.50 to 0.95, Mo: 0.20 to 0.30, P<=0.012, S<=0.010, Cu<=0.20, H<=2ppm, O<=50ppm, N<=85ppm, balance Fe; and a manufacturing method comprises the following steps of: secondary refiningand smelting by an electric furnace, and casting for forming ingot; heating and forging, with a heating speed of 100 to 150DEG C / h to rise the temperature to 1190 to 1230DEG C, and then preserving the heat for over 8 hours; forging steel ingot to have the size of a finished product; forging temperature range: 800DEG C to 1130 DEG C; adopting an upsetting drawing process, with a forging ratio >=6;and air cooling to reach a temperature of between 420 and 470DEG C after the forging and preserving the heat for over 2 hours, normalizing, with a temperature of between 870 and 890DEG C, and annealing, with a temperature of between 670 and 690DEG C. The indexes such as yielding, tensile strength, grain size and non-metallic inclusion of the forge piece meet the designed 105MPa pressure demand, and the forge piece is corrosion resistant.

Description

technical field

[0001] The invention relates to a hydrogen sulfide stress corrosion resistant high pressure forging for a large blowout preventer and a manufacturing method thereof. Background technique

[0002] During downhole operations, when the formation is open, if effective measures cannot be taken to control the high bottom pressure, bottom fluid (oil, gas and water) may flow into the wellbore uncontrollably and spray to the ground in large quantities. This is a blowout . Blowout accidents have great harm to the life and property safety of personnel near the well site, the environment around oil and gas wells, and underground oil and gas resources. Therefore, a blowout preventer should be installed at the oil well / gas wellhead, and it should be activated urgently to seal the wellhead when a blowout occurs, so as to avoid large economic losses.

[0003] The blowout preventer not only bears the huge pressure at the bottom of the oil well, but also bears the H in the o...

Examples

Embodiment 1

[0053] Its chemical composition is shown in Table 1, and the rest are Fe and unavoidable impurities;

[0054] Table 1

[0055]

[0056] After electric furnace smelting, refining outside the furnace and vacuum degassing, 35 tons of steel ingots are poured, demoulded and sent to the fast forging heating furnace for heating 12 hours after casting. The heating rate is heated to 1210°C and then kept for 8 hours. The heating process curve is shown in figure 1 Shown; the heating rate of the steel ingot and the soaking time in the high temperature section are controlled reasonably.

[0057] figure 2 It is a process curve diagram of normalizing and tempering treatment of forgings according to the present invention. Pre-normalizing treatment is carried out by air cooling after forging, and the temperature is kept at 420-470 ° C for 2 hours. The normalizing temperature is 870-890°C, and the holding time is 21 hours, so that the structure can be fully transformed and stable austen...

technical field

[0001] The invention relates to a hydrogen sulfide stress corrosion resistant high pressure forging for a large blowout preventer and a manufacturing method thereof. Background technique

[0002] During downhole operations, when the formation is open, if effective measures cannot be taken to control the high bottom pressure, bottom fluid (oil, gas and water) may flow into the wellbore uncontrollably and spray to the ground in large quantities. This is a blowout . Blowout accidents have great harm to the life and property safety of personnel near the well site, the environment around oil and gas wells, and underground oil and gas resources. Therefore, a blowout preventer should be installed at the oil well / gas wellhead, and it should be activated urgently to seal the wellhead when a blowout occurs, so as to avoid large economic losses.

[0003] The blowout preventer not only bears the huge pressure at the bottom of the oil well, but also bears the H in the o...

Examples

Embodiment 1

[0053] Its chemical composition is shown in Table 1, and the rest are Fe and unavoidable impurities;

[0054] Table 1

[0055]

[0056] After electric furnace smelting, refining outside the furnace and vacuum degassing, 35 tons of steel ingots are poured, demoulded and sent to the fast forging heating furnace for heating 12 hours after casting. The heating rate is heated to 1210°C and then kept for 8 hours. The heating process curve is shown in figure 1 Shown; the heating rate of the steel ingot and the soaking time in the high temperature section are controlled reasonably.

[0057] figure 2 It is a process curve diagram of normalizing and tempering treatment of forgings according to the present invention. Pre-normalizing treatment is carried out by air cooling after forging, and the temperature is kept at 420-470 ° C for 2 hours. The normalizing temperature is 870-890°C, and the holding time is 21 hours, so that the structure can be fully transformed and stable austen...

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