Submerged-arc welding wire for high-strength pipeline steel

Abstract

The present invention relates to the high intensity pipeline steel burying arc solder. It solutes the question that because of the Cu's deposition, it leads to separate out Cu easily and ossify the steel in the smelting and the disposal of the heat and contains too many microelements so that it has disbennifits to the smelting technical control. The technical steps are that the weight percent of the chymic component is C 0.04~0.12,Si 0.005~0.10,Mn 1.20~2.00,Ni 0.10~0.60,Cr 0.10~0.60,Mo 0.10~0.50,Ti 0.04~0.15,B 0.002~0.012,P<=0.015,S<=0.01, and the allowance is Fe. The invention solders matchingly with the alkalescence sinter flux. The resist drawing intensity of the welding line is higher than 650MPa.The intensity of the welding line of the jointing X80 pipe line steel reaches 740MPa, and the -20 Deg. C concussion power is higher than 120J.Then the content of the welding line S and P is low and the degree of purity is high. It applies to the burying arc jointing of the X80 high intensity pipeline steel and the other corresponding intensity low levels' alloy which resisted drawing intensity is between 620 and 740MPa.

Description

technical field [0001] The invention relates to a submerged arc welding wire for multi-element alloyed high-strength pipeline steel, in particular to a high-strength pipeline steel whose tensile strength is higher than 650 MPa when welding with alkaline sintering flux. Other low alloy high strength steel with submerged arc welding wire. Background technique [0002] With the application of advanced steel production technology, the performance of low-alloy high-strength steel has been continuously improved. Pipeline steel represents the advanced level of today's low-alloy high-strength steel. API X80 steel is the main pipeline steel variety in the world, and it will be gradually applied in my country. The S content of pipeline steel is getting lower and lower, and the steel quality is getting purer. The metallographic structure is ferrite plus bainite, and the grain diameter reaches several microns. The strength and toughness of the pipeline steel are improved simultaneou...

AI Technical Summary

Problems solved by technology

The tensile strength of the existing submerged arc welding wire used for X70 steel is 550-620 MPa, and the welding wire used is such as the two patents of the Chinese patent No. 92 1 05621.4 and the patent No. 97 1 04393.0. If it is to match the strength of X80 steel , the tensile strength of welding wire weld metal reaches 670-740MPa, and has excellent toughness, obviously there is a mismatch

The Chinese patent number is ZL 01 106520.6, which contains Cu and Zr. Although the tensile strength of the weld metal can reach 590Mpa and has high toughness, But its deficiencies: Cu is unfavorable to the impact toughness of steel, and there is precipitation hardening phenomenon, which leads to the increase of thermal brittleness after heat treatment of the weld, which is unfavorable to the heat treatment performance of the weld, and there are many types of trace elements, which is unfavorable to the control of the smelting process and increases the smelting process. difficulty