Development Of Flux Confined Arc Welding Method And Its Surfacing Technology Test

The flux sheet constrained arc method has significant advantages in ultra-narrow gap welding.In the ultra-narrow gap welding,the flux sheet restrains the arc,prevents the arc from climbing along the side wall,and effectively controls the arc heating area to ensure effective fusion of the two side walls of the groove.When the welding method is used to constrain the arc welding,the weld groove gap width is only 4 mm,and the welding heat input is low,only 0.5 KJ/mm,which can reduce the residual deformation and residual stress after welding,and the resulting overheating zone is very small.To 1 mm,the welded joints have good toughness.At the early stage of the welding process test,it was found that the placement of the flux sheet in the groove,the distance between the wire and the flux sheet,and the distance between the lower edge of the flux sheet and the bottom of the groove play a key role in the welding process.In order to solve the problems in the flux confinement arc welding method,a structure of a flux sheet chain is designed.On the one hand,the distance between the wire and the flux sheet can be controlled.On the other hand,the lower edge of the flux sheet and the bottom of the groove can be ensured.The distance is in a suitable range and the flux sheet can be tightly attached to both side walls of the groove.The flux sheet chain is made of a flux sheet bonded to a glass fiber mesh.In order to woven fiberglass mesh with high efficiency and high quality,a webbing machine is used to achieve the purpose of automated weaving.Glass fiber mesh consists of warp and weft.Since the warp threads in the glass fiber mesh have good elasticity,the distance between the welding wire and the flux sheet can be controlled.The weft thread is coated with a reinforcing sizing agent to increase the hardness of the weft thread.It is ensured that the flux sheet chain is bent into a U shape in the welding groove,so that the flux sheet is tightly attached to both side walls of the groove.The preparation of the flux sheet is performed in accordance with the alkaline electrode formulation and the manufacturing process.The key to the production of flux sheets is the grain size of the dry powder and the grain size and dryness of the wet powder,which directly affect the yield and strength of the flux sheet.It is required that the strength of the flux sheet beas high as possible in order to ensure that the manufactured flux sheet will not be easily broken or damaged during storage and transportation,or that it will not be easily damaged during arrangement,manufacture and use in the groove.The production of the flux sheet chain is completed on the flux sheet chain production device.The key to the production of the flux sheet chain lies in the choice of the binder and how to efficiently bond the flux sheet to the glass fiber web.The flux sheet is bonded to the warp threads of the glass fiber mesh,and the warp of the glass fiber mesh uses its own elasticity to control the distance between the wire and the flux sheet,so the selected binder has poor permeability and cannot be impregnated into the glass fiber.Inline reduces its elasticity.The experimental adhesives selected fast-ab epoxy adhesive,which has poor permeability and short film-drying time.The solder sheets can be bonded to the glass fiber web in a short time.The application of this method in surfacing welding was explored based on the ultra-narrow gap welding constrained arc welding method.The key to the surfacing process design is the alloying and dilution of the surfacing metal.Since the flux sheet constrains the arc to a narrow gap,the welding groove width is only 4mm,and the welding heat input is low,which can reduce the dilution rate of the base metal;in addition,it can be flexibly implemented.The required alloying elements are added to the flux sheet in a certain proportion,and the alloying elements can be transitioned into the welds through the burning of the fluxing sheet in the welding.The use of flux sheet constrained arc welding methods does not require shielding gas,and is not subject to the influence of external environmental winds.