| At present domestic stainless steel flux-cored wire are mainly composed of gas protection. Series products of self-shielded stainless steel flux cored wire have not been formed. The austenitic stainless steel self-protection flux cored wire E308LT0-3 is researched,the effect of pretreatment temperature on the liquidity and uniformity of powder and the influence of mineral composition of powders on the process performance have been studied.the predominantly slag system composed of Ba F2-Ca O-Ti O2-Si O2 is determined. A kind of flux-cored wire with stable quality and good welding technological properties is developed,for the development of austenitic stainless steel self-protection flux cored wire laid a solid foundation.Due to the addition of large amounts of carbonates and fluorides, the powder has poor liquidity and uniformity, which seriously affect the quality stability of the wire.. In order to research the impacts, Carr index method and standard deviation method is used to characterize liquidity and uniformity of powder which through different pretreatment temperature, and SEM is used to observe the microstructure of powder particles. The results shows that with the increase of pretreatment temperature, liquidity and uniformity of the powder were improved, the surface states of powder particles turned Flake into a ball.Flux-cored wire with stable quality can be producted when the pretreatment temperature reaches 700?.The optimum proportion of mineral composition is the difficulty and emphasis in the process of the development of flux cored wire, In order to explore the optimum proportion components, extreme vertex blending regression method and the Design Expert software is used to make experiment design. The formula of the regression equation on the individual welding performance(deslagging rate, splash rate, weld formation, arc stability) of the mineral components was built. The equation of 3D surface figure and corresponding binary contour diagram is obtained. Using the function of optimization solution, the optimum proportion components of this slag system with high comprehensive process property is obtained, and It has been verified by the actual.High speed photograph and Hannover Analysator are used to study Melting drop transition form of welding process, Under the same welding parameter, transition form of flux-cored wire with different mineral components ratio contains short circuiting transfer,big drop out transition and fine particles transition. Through welding process experiment,fine particles transition is determined as the ideal metal transfer form, and the welding technology range of the basic formula is U=(25-32)V,I=(200-310A) is ensured. |
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