Home  >  Hot News  >  Current News

Welding Process of Petroleum Casing Pipe

Date:2020-07-02    keywords:petroleum, casing pipe, welding process
Welding process of oil casing pipe
(1) Selection of welding method: 80%Ar+20%CO2 gas shielded welding.
Selection of welding data: ER55-G welding wire is used, with a diameter of 3.2mm.
Welding parameters: current 250~320A, voltage 26~30V;
The welding speed is 35~50cm/min; the preheating temperature is 100℃, to ensure that the temperature between the layers is not lower than the preheating temperature, but it is not allowed to be 30℃ higher than the preheating temperature.
Post-weld treatment: air-cooled without any heat treatment.

(2) Selection of welding method: 80%Ar+20%CO2 gas shielded welding.
Selection of welding data: ER55-G welding wire is used, with a diameter of 3.2mm.
Welding parameters: current 250~320A, voltage 26~30V; welding speed 35~50cm/min; preheating temperature is 100℃, to ensure that the interlayer temperature is not lower than the preheating temperature, but also not allowed to be higher than the preheating temperature 30℃ .
Post-welding treatment: tempering treatment, temperature 600±20℃, holding time 4h; heating rate 50℃/h, cooling rate 50℃/h.

The test blocks welded by the above two welding processes have the following experimental results:
The results of the first (1) plan: tensile test, broken base material, qualified; impact value of 3 samples in heat affected zone 26, 47, 23, unqualified; four samples of side bending have 3.75mm Cracks, 4mm cracks, 1.38mm cracks, 0.89mm cracks, failed; the experiment proved that this process plan is unreasonable.
The results obtained from the plan (2): tensile test, broken base material, qualified; impact value of three samples in heat affected zone 51, 40, 40, qualified; all four samples of side bending are qualified, qualified; Experiments prove that this process plan is reasonable. Post-weld heat treatment can improve the performance of the welded structure, which is one of the important factors for whether the 37Mn5 petroleum casing can be welded to meet the technical requirements.

©2017 Permanent Steel Manufacturing Co.,Ltd All Rights Reserved.  Terms of Sale|Privacy Policy