Submerged arc welding flux material used for high grade pipe line steel

Abstract

The present invention provides a welding flux material for submerged arc welding for welding high-grade line pipe steel and other structure steel. Its chemical composition includes (by wt%) 15%-25% of CaF2, 15%-25% of MgO, 15%-20% of Al2O3, 5%-10% of MnO, 5%-10% of TiO2, 10%-15% of SiO2, 5%-10% of CaO, 1.0%-2.5% of Na2O, 1.5%-3.0% of B2O3, 0.2%-0.4% of Re(Mg) and 3%-5% of ZrO2. Said welding flux material can be prepared by adopting sintering process. Besides, said invention also provides its application method.

Description

Technical field

[0001] The invention belongs to the technical field of welding, and relates to a flux material, in particular to a submerged arc welding flux material for high-grade pipeline steel. Background technique

[0002] Oil and natural gas transmission pipelines are usually located in areas with relatively harsh environments, such as extremely cold areas, seismic zones or ocean areas. The requirements for high strength and low temperature toughness of transmission pipelines are increasing, which has prompted high-grade pipeline steel (X80 pipeline steel) The successful development of X80 pipeline steel has been hailed as the steel for natural gas transmission pipelines in the 21st century by industrially developed countries. High-strength pipeline steel requires high strength and good low-temperature toughness, and matching high-quality welding materials has also become one of the focuses of attention. In order to improve the strength and toughness of long-distance pipeli...

Examples

Embodiment 1

[0037] Take 20% CaF by weight percentage 2 , 24% MgO, 13% Al 2 O 3 , 8% MnO, 8% TiO 2 , 12% SiO 2 , 6% CaO, 2.5% Na 2 O, 1.9% of B 2 O 3 , 0.2% Re(Mg), 4.4% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0038] The flux is matched with H08C welding wire to weld 7.9mm thick X80 grade pipeline steel. The chemical composition of the steel mainly contains C 0.063%, Mn 1.83%, Si 0.28%, Mo 0.22%, Ni 0.03%, Cr 0.03% by weight. Nb 0.04%, Ti 0.016%, B 0.0006%, V 0.059%, Nb 0.061, S 0.006%, P 0.011%. The chemical composition of H08C welding wire mainly contains C 0.87%, Mn 1.44%, Si 0.147%, Cu 0.22%, Mo 0.34%, P 0.02%, and S 0.004% by weight percentage. The welding process is not to open the groove, the front and the back are welded, and the back is cleaned. The welding process parameters are welding current of 520A on the first side, 550A on the second side, welding voltage of 32V, and welding speed of 2...

Embodiment 2

[0046] Take 22% CaF by weight percentage 2 , 20% MgO, 16% Al 2 O 3 , 8% MnO, 8% TiO 2 , 10% SiO 2 , 8% CaO, 1.8% Na 2 O, 2% of B 2 O 3 , 0.2% Re(Mg), 4% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0047] The flux is matched with H08C welding wire to weld 15mm thick X80 grade pipeline steel. The chemical composition and welding process of the steel are the same as in Example 1. The welded joints are inspected according to API 5L standard, and the cold bending performance is qualified. The tensile and hardness test results are shown in Table 3, and the impact test results are shown in Table 4.

[0048] Table 3 Tensile and hardness test of X80 pipeline steel welded joint

[0049]

Item

σ S (Mpa)

σ b (Mpa)

σ S / σ b

δ 5 / %

Hardness

(Hv10)

Match

H08C

560.0～588.5

630.7～680.9

0.86～0.88

16.7～19.3

229～240

...

Embodiment 3

[0053] Take 20% CaF by weight percentage 2 , 23% MgO, 16% Al 2 O 3 , 8% MnO, 8% TiO 2 , 10% SiO 2 , 8% CaO, 1% Na 2 O, 2.6% of B 2 O 3 , 0.4% Re(Mg), 3% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0054] The flux is matched with H08C welding wire to weld 15mm thick X80 grade pipeline steel. The chemical composition and welding process of the steel are the same as in Example 1. The welded joints were inspected according to API 5L standard, and the cold bending performance was qualified. The tensile and hardness test results are shown in Table 5, and the impact test results are shown in Table 6.

[0055] Table 5 Tensile and hardness test of welded joint of X80 pipeline steel

[0056]

Item

σ S (Mpa)

σ b (Mpa)

σ S / σb

δ 5 / %

Hardness

(Hv10)

Match

H08C

570.0～593.5

640.7～677.9

0.88～0.89

15.5～19.2

220～240 ...

Technical field

[0001] The invention belongs to the technical field of welding, and relates to a flux material, in particular to a submerged arc welding flux material for high-grade pipeline steel. Background technique

[0002] Oil and natural gas transmission pipelines are usually located in areas with relatively harsh environments, such as extremely cold areas, seismic zones or ocean areas. The requirements for high strength and low temperature toughness of transmission pipelines are increasing, which has prompted high-grade pipeline steel (X80 pipeline steel) The successful development of X80 pipeline steel has been hailed as the steel for natural gas transmission pipelines in the 21st century by industrially developed countries. High-strength pipeline steel requires high strength and good low-temperature toughness, and matching high-quality welding materials has also become one of the focuses of attention. In order to improve the strength and toughness of long-distance pipeli...

Examples

Embodiment 1

[0037] Take 20% CaF by weight percentage 2 , 24% MgO, 13% Al 2 O 3 , 8% MnO, 8% TiO 2 , 12% SiO 2 , 6% CaO, 2.5% Na 2 O, 1.9% of B 2 O 3 , 0.2% Re(Mg), 4.4% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0038] The flux is matched with H08C welding wire to weld 7.9mm thick X80 grade pipeline steel. The chemical composition of the steel mainly contains C 0.063%, Mn 1.83%, Si 0.28%, Mo 0.22%, Ni 0.03%, Cr 0.03% by weight. Nb 0.04%, Ti 0.016%, B 0.0006%, V 0.059%, Nb 0.061, S 0.006%, P 0.011%. The chemical composition of H08C welding wire mainly contains C 0.87%, Mn 1.44%, Si 0.147%, Cu 0.22%, Mo 0.34%, P 0.02%, and S 0.004% by weight percentage. The welding process is not to open the groove, the front and the back are welded, and the back is cleaned. The welding process parameters are welding current of 520A on the first side, 550A on the second side, welding voltage of 32V, and welding speed of 2...

Embodiment 2

[0046] Take 22% CaF by weight percentage 2 , 20% MgO, 16% Al 2 O 3 , 8% MnO, 8% TiO 2 , 10% SiO 2 , 8% CaO, 1.8% Na 2 O, 2% of B 2 O 3 , 0.2% Re(Mg), 4% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0047] The flux is matched with H08C welding wire to weld 15mm thick X80 grade pipeline steel. The chemical composition and welding process of the steel are the same as in Example 1. The welded joints are inspected according to API 5L standard, and the cold bending performance is qualified. The tensile and hardness test results are shown in Table 3, and the impact test results are shown in Table 4.

[0048] Table 3 Tensile and hardness test of X80 pipeline steel welded joint

[0049]

Item

σ S (Mpa)

σ b (Mpa)

σ S / σ b

δ 5 / %

Hardness

(Hv10)

Match

H08C

560.0～588.5

630.7～680.9

0.86～0.88

16.7～19.3

229～240

...

Embodiment 3

[0053] Take 20% CaF by weight percentage 2 , 23% MgO, 16% Al 2 O 3 , 8% MnO, 8% TiO 2 , 10% SiO 2 , 8% CaO, 1% Na 2 O, 2.6% of B 2 O 3 , 0.4% Re(Mg), 3% ZrO 2 , Add ore powder mechanical mixture, sinter by conventional electric furnace sintering method, sintering temperature is 750℃.

[0054] The flux is matched with H08C welding wire to weld 15mm thick X80 grade pipeline steel. The chemical composition and welding process of the steel are the same as in Example 1. The welded joints were inspected according to API 5L standard, and the cold bending performance was qualified. The tensile and hardness test results are shown in Table 5, and the impact test results are shown in Table 6.

[0055] Table 5 Tensile and hardness test of welded joint of X80 pipeline steel

[0056]

Item

σ S (Mpa)

σ b (Mpa)

σ S / σb

δ 5 / %

Hardness

(Hv10)

Match

H08C

570.0～593.5

640.7～677.9

0.88～0.89

15.5～19.2

220～240 ...

Images