| With the development of modern manufacturing process,the mold has been widely applied to the manufacturing industry production to improve the efficiency of production and processing.The TD salt-bath is one of the important mold surface modification methods of improving the properties of mould effectively.TD salt-bath permeability vanadium research has had a history of more than forty years,but the TD salt-bath carburizing process,equipment and practical aspects of vanadium still existed many problems to be resolved,like the lackness of effective experimental data and analysis conclusion that provide reference data for industrial application to promote infiltration vanadium in the application of mold manufacturing.Taking the vanadizing materials of Cr12 steel as research material,borax salt bath vanadizing process test and orthogonal test scheme are used.By comparing the optimization of salt bath formulations and process parameters and adding amount of rare earth neodymium(Nd)is selected to study the Influence Factors of carburized layer and properties of vanadium coating.In this paper,the Cr12 material performance and characteristics are analyzed.The paper studied the borax bath salt bath reagent and the added percolation theory basis of vanadium and ultimately come to determine the basic formula of salt bath.Firstly several key factors influenc-ing the selected coating thickness in the salt bath process was chose,such as salt bath heating temperature,holding time,adding amount of rare earth,etc.Then the paper choose the method of orthogonal experiment on the several key factors to analyze the influence of the thickness of cladding and the contrast of the salt bath in the use of different materials of crucible by selecting the crucible of several representative of salt bath experiment material.Then the corrosion in salt bath on fixture material is studied and influence of reducing agent and temperature on the flow of molten salt experiment is carried out and analyzed.In the cend,the salt bath furnace crucible through the comparison and analysis of material selection,structure optimization.In order to make the stamping die get cladding quality,also cannot leave the good design method.This paper introduces the sheet metal module of Pro/E,and the PDX plug-in module used for professional stamping die design software,and the application of the design of evaporator tube plate cold stamping die.By-using optical microscope,micro hardness tester,SEM and EDS and other modern analysis methods of research,this paper comes to the conclusions as follows:Permeability of vanadium salt bath temperature is not the higher the better,and there exists a critical temperature.When it exceed much more than the temperature conditions,The material substrate surface will not generate the cladding material substrate.Using orthogonal experiment method in this study,the optimum coating thickness can obtain optimal conditions that adding 1.3%rare earth,the heat to 960 ℃,insulation 4h.Increasment of the addition amount of rare earth neodymium in salt bath heat treatment,can contribute the hardness of a smooth transition transition region between coating and matrix.In the graphite crucible surface coated with a layer of titanium dioxide can improve the crucible corrosion ability;reduction of agent Al can make the fused salt liquidity,temperature of molten salt improved liquidity best at 1020℃.Clamp experiment material thermal insulation 4H at 960 ℃ high temperature,molten salt on the specimen material most deep etching depth can reach 0.3mm,and produced a large amount of iron parts in above the surface oxide.The use of chromium nickel alloy electric furnace wires and silicon carbide furnace can prolong the service life of the salt bath furnace.The use of plug-in PDX design Pro/E evaporator tube plate stamping die design cycle is shortened to 1/3 of the original,which can reduce the cost of mold design while mold design error is small and the structure of high is of accuracy. |
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