Electric welding rod for gas shielded welding X80 grade steel oil, gas transmission pipe

Abstract

The invention discloses a gas-shielded welding wire used for the production of grade X80 steel and oil and gas transferring. The gas-shielded welding wire comprises the following chemical compositions (according to the weight percentage): 0.08-0.12 percent of C, 1.40-2.0 percent of Mn, 0.30-0.70 percent of Si, larger than 0 and smaller than or equal to 0.015 percent of P, larger than 0 and smaller than or equal to 0.015 percent of S, 0.20-0.40 percent of Mo, 0.10-0.35 percent of Cu, 0.10-0.2 percent of Ti, 0.15-0.40 percent of Cr, 0.65-0.90 percent of Ni, 0.004-0.008 percent of B, 94.9-97.0 percent of Fe, and impurity for the residual; the gas-shielded welding wire is produced according to the production technique of common gas-shielded welding wire. The pipe used for production has the following welding seam performances: the tensile strength is 665-750MPa, the yield strength is 555-680MPa, the specific elongation is 20-29 percent, the hardness is 205-236HV10, the Charpy Impact energy is Akv(-10 DEG C)=230-262J, and the shearing area is 66-73; the Charpy Impact energy of the heat affected zone is Akv(-10 DEG C)=224-268J, the shearing area is 75-83, the performances are greatly superior to the requirements on the welding seam performance of the grade X80 steel pipe, the gas-shielded welding wire has excellent performances such as high strength, high toughness, good corrosion resistance, low hardness and the like which are similar to the performances of the pipe body, the security of pipe transportation can be effectively enhanced, and the service life of the pipe transportation can be prolonged.

Description

technical field [0001] The invention belongs to welding wire for metal material welding, in particular to a gas-shielded welding wire for welding production of X80 grade steel oil and gas delivery pipes. After the pipe (body) is welded with the welding wire, the weld seam has excellent performances such as high strength, high toughness, good corrosion resistance and low hardness similar to the pipe body. Background technique [0002] Pipeline transportation is the most ideal transportation method for long-distance transportation of oil and natural gas. It has the characteristics of economy, safety, high efficiency, energy saving, uninterrupted, and less damage to the environment. Therefore, all countries in the world attach great importance to the development of pipeline transportation technology, and many countries spare no effort to spend a lot of financial and material resources to vigorously develop the pipeline transportation industry. Pipeline transportation has becom...

AI Technical Summary

Problems solved by technology

In the patent document with the patent number 200810052501 and the invention name "X80 Steel Grade Pipeline Steel Gas Shielded Welding Solid Wire", a composition by weight percentage is disclosed: C 0.04-0.08%, Mn 1.40-2.0%, Si 0.40-0.70%, 0<P≤0.015%, 0<S≤0.015%, Mo 0.25-0.45%, Ni 0.80-1.0%, Cu 0.08-0.20%, Ti 0.03-0.06%, the rest is Fe and unavoidable Gas shielded welding wire with impurities, due to the lack of Cr element and insufficient Ti element content in the welding wire composition, the oxidation resistance and corrosion resistance of the weld are worse than that of X80 grade steel, with low toughness and high hardness. Defects such as poor performance matching between seam and X80 pipe body