The invention belongs to the field of welding, in particular to a process method applicable to marine engineering large thick steel plate submerged arc welding in low-temperature environment, which comprises a welding method, welding material selection, a welding order, a welding process and the selection and control of various welding process parameters. The method renders with carbon dioxide gas protection welding, and fills and faces through an automatic submerged arc welding; stops welding when the welding reaches more than two thirds of the thickness of a large groove during the welding process, clears chips on the back side and completes the welding of the other side; finally completes the welding of the first side; strictly controls all relevant process parameters of the welding during the welding process, and solves the problems of poorer anti-crack toughness of welding seams and heat affected zones caused by too high cooling speed of the welding seams and too high temperature; can ensure good anti-crack toughness of a welding seam connector without heat treatment after welding; and can meet the requirements of welding of an E36 plate with the thickness of 35 to 77mm underthe working environment at the temperature of above -30DEG C, simplifies the production process, shortens the production cycle and reduces the cost.

Marine engineering large thick steel plate submerged arc welding process method in low-temperature environment

The invention discloses a solder wire for submerged arc welding of X100 pipeline steel, which consists of the following components in percentage by weight: 0.03 to 0.06 percent of C, 0.1 to 0.3 percent of Si, 1.0 to 2.0 percent of Mn, 0.7 to 1.0 percent of Ni, 0.3 to 0.6 percent of Mo, 0.3 to 0.6 percent of Cr, 0.01 to 0.04 percent of Nb, 0.1 to 0.3 percent of Ti, 0.0015 to 0.005 percent of B, 0.1 to 0.3 percent of Cu, 0.1 to 0.3 percent of Ce, 0.01 to 0.05 percent of Al, less than 0.01 percent of S, less than 0.01 percent of P and the balance of Fe. The solder wire has the advantages of high strength of welding lines, good impact property and the like. The invention also discloses a preparation method for the solder wire, which comprises the following steps of: smelting Fe, Nb and the like in a vacuum induction furnace, raising the temperature to 1,540 DEG C, keeping the temperature, and after the molten steel is calm, cooling and exhausting; refining, reducing temperature, performing fine adjustment on Ti content, introducing a protective gas Ar before tapping, simultaneously adding components such as Mn, Fe and the like, stirring, tapping and casting to obtain steel ingots; and performing subsequent forging, rolling and drawing on the steel ingots, and finally obtain solder wires. The preparation method for the solder wire is stable in smelting process and easy to implement; and the product has good properties.

Solder wire for submerged arc welding of X100 pipeline steel and preparation method thereof

The invention discloses a high-strength and high-tenacity gas shielded welding wire. The welding wire comprises the following chemical composition in percentage by mass: 0.02 to 0.12 percent of carbon (C), 1.20 to 2.10 percent of manganese (Mn), 0.20 to 1.00 percent of silicon (Si), less than or equal to 0.010 percent of sulfur (S), less than or equal to 0.015 percent of phosphorus (P), 2.00 to 3.50 percent of nickel (Ni), 0.20 to 0.80 percent of molybdenum (Mo), 0.20 to 0.30 percent of titanium (Ti), 0.60 to 1.20 percent of chromium (Cr), less than or equal to 0.05 percent of vanadium (V), 0.005 to 0.010 percent of boron (B), less than or equal to 0.015 percent of aluminum (Al), less than or equal to 0.35 percent of copper (Cu) and the balance of iron (Fe). The welding wire is used for welding steels of a strength grade of between 850 and 950MPa; and under the protection of a mixed gas (80 percent of argon (Ar) and 20 percent of carbon dioxide (CO2)), the weld metal tensile strength of the welding wire is more than or equal to 850MPa, the yield strength is more than or equal to 720MPa, the elongation is more than or equal to 22 percent, and the low-temperature impact toughness Akv is more than or equal to 181J at the temperature of -30 DEG C, or more than or equal to 175J at the temperature of -40 DEG C, or more than or equal to 162J at the temperature of -50 DEG C.

High-strength and high-tenacity gas shielded welding wire

The invention discloses a method of submerged-arc welding of a thick sheet S355NL for a low-temperature wind tower, which comprises the following steps: adopting an S355NL thick sheet satisfying requirements for chemical composition, weight percentage and technical conditions, wherein the carbon equivalent Ceq of steel is less than or equal to 0.42 percent; using welding wires satisfying requirements for chemical composition and weight percentage; adopting symmetric double-sided X type grooves as submerged-arc welding groove, wherein the groove angle is 60 degrees, the groove gap is 0.5mm, and when the thickness of the sheet is less than or equal to 50mm and the ambient temperature is no lower than 10 DEG C, no preheating is needed for welding; and selecting welding parameters, wherein the welding heat input is less than or equal to 50KJ/cm. The invention realizes the welding process that no preheating is needed prior to welding and no heat treatment is needed after welding during manufacture of the thick sheet structure of the butt joint of the steel plate S355NL for the low-temperature wind tower in marine and cold regions. Due to the multi-layer multi-channel continuous welding, the welded joint has excellent comprehensive mechanical properties, and weld joints and weld heat-affected zones has large impact toughness reserves and safety margins. Therefore, the invention is suitable for promotion and application in the manufacture of the low-temperature wind tower in the factory.

Method of submerged-arc welding of thick sheet S355NL for low-temperature wind tower

The invention discloses a low-alloy super-strength steel high-flexible buried arc solder wire, which comprises the following parts: 0.06-0.12% C, 0.03-0.20% Si, 1.50-2.00% Mn, 0.20-0.60% Cr, 1.40-2.60% Ni, 0.10-0.50% Mo, 0.10-0.60% Cu, 0.06-0.20% Ti, 0.002-0.010% B and Fe and impurity. The solder wire mates the alkaline sintered welding agent with tensile strength of welding seam not less than 800Mpa, which possesses impacting flexibility AKV not less than 47J at -40 deg.c.

High ductility buried arc welding wire for low-alloy super-strength steel

The invention discloses a gas-shielded welding method for high-strength bridge steel, which comprises the following steps: (1) the high-strength bridge steel with the tensile strength of between 570 and 650MPa and the thickness of 50 millimeters is adopted, a matched welding material is adopted, wherein the tensile strength of a welding wire is 570-660MPa, and the diameter of the welding wire is 1.2 mm; (2) a gas-shielded welding groove adopts a double V-shaped symmetrical groove, the angle of the groove is 60 DEG, and the truncated edge is 2 millimeters; (3) the welding process specification is as follows: the welding current is 23-27 A, the welding voltage is 23-27 V, the welding speed is 30-29 cm/m, the welding heat input is 12-15 kJ/cm, the argon-rich mixed gas metal arc welding with 20 percent of CO2 and 80 percent of Ar is adopted, the flow of gas is 18-20 L/min, no preheating is performed before welding, and no heat treatment is performed after the welding; and (4) the gas-shielded welding adopts multi-layer multi-pass continuous welding, and the interlayer temperature is controlled to between 100 and 150 DEG C. The welding method has the advantages of good welding processing property, simple and convenient operation, applicability, convenience, high efficiency, and energy conservation, and is applicable to the manufacturing, promotion and application of large-span bridge steel of factories.

High-strength bridge steel-gas protective welding method

The invention relates to a high-strength and high-toughness automatic submerged arc welding wire with weathering resistance and mainly aims at overcoming disadvantages of poor atmospheric corrosion resistance, high production cost and the like of the existing submerged arc welding materials. In term of technical measures, the welding wire is made from the following chemical components by weight percent: C: 0.05-0.12, Si: 0.01-0.10, Mn: 1.50-2.1. S: not more than 0.015, P: not more than 0.020, Ni: 0.20-0.60, Cr: 0.20-0.50, Cu: 0.25-0.50, Ti: 0.05-0.16, B: 0.002-0.010, Als: 0.001-0.015, Fe and other unavoidable impurities. The welding wire is matched with a basic sintered flux for welding, a weld joint has excellent atmospheric corrosion resistance and comprehensive mechanical properties, and a deposited metal at a weld seam has tensile strength up to 560MPa and ballistic work up to 107J at -40 DEG C and up to 87J at -50 DEG C.

High-strength and high-toughness automatic submerged arc welding wire with weathering resistance

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.

Submerged-arc welding wire for high-strength pipeline steel

The invention provides a manual welding process method of high strength bridge steel. The manual welding process method comprises the steps as follows: (1) the bridge steel with the tensile strength of 570-650MPa and the thickness of 32-60mm is taken as a base material for welding; the matching welding materials are as follows: the tensile strength of a manual electrode is 590-650MPa and the diameter Phi of the electrode is 4.0mm; (2) a groove is an X-shaped symmetrical groove and the groove angle is 60 degrees, the root face is 2mm; (3) the welding process parameters are as follows: the welding current is 165-170A, the welding voltage is 26-25V, the welding speed is 17-15cm/min, the weld line energy is 15-17kJ/cm and the baking system of the electrode is 350 DEG C multiplied by 1h; (4) the manual welding adopts continuous multilayer and multipass welding, the interlayer temperature is controlled within 100-150 DEG C. The manual welding process method of the invention is characterized by good welding process performance, simple operation, convenient use, high efficiency and energy conservation, and adaptation to the welding of steel for wide-span and high-strengthen bridge structure. The manual welding process method has excellent welding seam crack resistance, and three joint areas have relatively high impact toughness reserve and safety margin.

High intensity bridge steel manual welding technique method

The invention relates to a submerged arc welding butt welding technique for high intensity bridge steels, which is used for solving problems at present that in the submerged arc welding butt welding of making large span bridge structures by the bridge steels with low alloy and high intensity, the bridge steels need to be heat treated and back-gouged after being welded. The measure is as following: the method of the invention includes that the bridge steels with the tensile strength of 570MPa to 650MPa and the thickness of 36 to 60mm are used; the matched welding material meet the requirementsthat the tensile strength of welding wires is 600MPa, the diameter Phi of the welding wires is 5.0mm, the welding flux is SJ105Q; a submerged arc welding groove adopts a double-sided V shape asymmetrical groove, the groove angle is 60 degrees, the blunted edge is 6mm; the flame before the welding is preheated to 80 DEG C to 100 DEG C; the welding parameter includes that the welding current is 680A to 700A, the welding voltage is 29V to 30V, the welding speed is 22m/h to 23m/h, the welding line energy is 32kJ/cm to 35kJ/cm, the baking system of the welding flux is 350 DEG C multiplied by 1h; the submerged arc welding adopts the multi-layer and multi-channel continuous welding, and the interlayer temperature is controlled to be 100 DEG C to 160 DEG C. The submerged arc welding butt welding technique for the high intensity bridge steels is simple in procedure and low in energy consumption without the heat treating and the back gouging after being welded.

Kai Miao

Papers

High-strength bridge steel-gas protective welding method

High-strength and high-toughness automatic submerged arc welding wire with weathering resistance

Submerged-arc welding wire for high-strength pipeline steel

High intensity bridge steel manual welding technique method

Thick steel plate buried arc welding method for high-strength bridge