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 in particular relates to a welding process for super thick high strength steel plates for ships and provides a downward and butt welding process aiming at downward and butt welding of EH36Z 100mm-thick high strength steel plates for a ship structure. By putting forward effective specifications for welding grooves, weld preheating, welding temperature, welding sequence, welding variables and cold treatment after welding, the welding process of the high strength steel for super thick plates can be smoothly implemented; and by using the welding process, the labor efficiency is improved, the raw materials is saved, the production cost is reduced, the ship building period is shortened, large scale practical application of the steel to the engineering is successfully implemented for the first time and the gap in the technical specifications in welding of the EH36Z 100mm-thick high strength steel for thick plates for the ship structure at home is filled in.

Downward and butt welding process for high strength steel for ship structure

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 relates to a butt joint submerged-arc welding method of bridge steel with tensile strength more than 690Mpa grade, overcoming the defects that at the present, bridge steel and other engineering structural steel which are in 690Mpa strength grade needs preheating before welding and heat treatment after welding and has severe welding environment and the like during manual and gas protective welding. The butt joint submerged-arc welding method comprises the following steps: adopting steel with tensile strength Rm of between 690Mpa and 745Mpa, the yield strength ReL of between 550 and 690Mpa, the extension rate A of between 19 percent and 21 percent, KV2 ballistic work of between 165J and 180J at 40 DEG C below zero and the thickness of 40mmm, and adopting same-thickness butting;adopting matched welding wires with the tensile strength more than 690Mpa and diameter phi of 4.0mm, and using CHF105 as a welding flux; adopting a double-sided X-type asymmetrical submerged-arc welding groove with the angle of 60 degrees and the truncated edge of 5mm; continuously welding until welding seams are full, and under the conditions that the welding current is 570A, the voltage is 31V,the speed is 35cm/min and the linear energy is 30kj/cm; baking the welding flux for 1 hour at 350DEG C and keeping the temperature of welding layers between 100 DEG C and 150DEG C.

Butt joint submerged-arc welding method of bridge steel with tensile strength more than 690Mpa grade

The invention relates to a gas shielded welding wire with high strength and high toughness, which solves the defects that the existing strength grade in the technical field is unsuitable for market demand and is of high cost. The technical scheme of the invention is that the components of the welding wire (according to the weight percentage) are as follows: 0.04 to 0.10 of C, 0.30 to 0.80 of Si, 1.30 to 2.0 of Mn, 0.40 to 0.89 of Ni, 0.20 to 0.50 of Cr, 0.20 to 0.60 of Mo, 0.56 to 0.80 of Cu, 0.05 to 0.20 of Ti, 0.002 to 0.010 of B, less than 0.020 of P, less than 0.015 of S, less than 0.03 of Als and the rest of Fe and inevitable impurities. The welding wire of the invention has stable quality. The mechanical property of a deposited metal is that Rel is equal to 810MPa; Rm is equal to 840MPa; A is equal to 16 percent and Z is equal to 66 percent. The average impact power AKV in minus 20 DEG C is 141J; and the average impact power AKV in minus 40 DEG C is 128J; and the average impact power AKV in minus 60 DEG C is 70J. The welding wire is suitable for gas shielded welding of 800MPa grade of ultra-fine steel; as the content of Ni is reduced, the cost of the welding wire is reduced dramatically and the implementation is easy.

High-strength high ductility gas protecting welding stick

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 discloses a submerged arc-welding method of thick steel slab for large pressure vessel with tensile strength of 610-670 MPa, which solves the currently existing defects that the impact energy of deposited metal and the actual joint tenacity can not meet the welding requirements for the production of large high-strength thick steel slab structure. A measure adopted by the invention is as follows: the method comprises the following steps of: adopting pressure vessel steel with tensile strength of 610-670 Mpa and thickness of 44mm to 55mm; using matched welding materials: the tensile strength of a welding wire is 610-670 Mpa with diameter of 4.0mm and welding flux SJ105Q is adopted; adopting an unsymmetrical double-side V-shaped groove with an angle of 60 degrees as the groove of submerged arc-welding and a blunted edge of 4mm; continuously welding at the butt joint till weld seams are filled up under the conditions of 700A welding current, 36V voltage, 30cm/min speed and 50kJ/cm energy input; using a welding flux roasting system of 350 DEG C multiplied by 1h; and adopting interlayer temperature of 100 DEG C to 150 DEG C. In the invention, preheating is not required before welding and heat treatment is not needed after welding and joints have good low temperature impact toughness and safety storage.

Submerged arc-welding method of steel for high strength pressure vessel

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.

Zhijun Huang

Papers

Butt joint submerged-arc welding method of bridge steel with tensile strength more than 690Mpa grade

High-strength high ductility gas protecting welding stick

High-strength bridge steel-gas protective welding method

Submerged arc-welding method of steel for high strength pressure vessel

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