Research On High Temperature Performance Of Mould Materials With High Current Pulsed Electron Beam Alloying

Mould industry hold an important position in the modern manufacturing, 50% finish machining and 75% rough machining is manufactured by mould, the mould consumption accounting for very high proportion in the cost of parts production, Usually the proportion is 40%, and 80% disabled form of die is surface damage. With the development of modern industry, there has urgently needs to invigorating the mould industrial.With the development of the industry, the working conditions of dies become increasingly worse, for the dies which work in the high-temperature conditions, the high temperature oxidation performance and thermal fatigue performance of the die material determines the lifespan of mould. The high temperature oxidation performance is the mainly and the most important corrosion types of the die material under the high-temperature conditions, and the thermal fatigue performance determines whether the surface of the die material will produce the microcrack under the action of thermal cycle, both of them will lead the ineffectiveness of the die. The electron beam surface modification is a new technology, which makes up the short of conventional techniques, we believe that with the development of this new technology, the industry advance rapidly. We make die surface alloying with the electron beam surface alloying technology, to improve the high- temperature performance of die material without deteriorating the mechanical properties, and analyze the mechanism, and enhance the lifespan of the mould.We use the ANSYS 12.0 to simulate the process of 3Cr2W8V electron beam surface alloying Al,Surface treatment and surface alloying of 3Cr2W8V have been carried out by electron beam equipment which is made in Russia, the alloying materials are Al, Ti and TiN, So was the 40Cr, but the alloying material of 40Cr is only Al . We are combining the finite-element simulations with experiment, and summarize the conclusion as followed: 1) The influence of Al to the electron beam surface alloying process. 2) The influence of electron beam surface alloying to the mechanical properties of material. 3) The influence of electron beam surface alloying to the high temperature performance of material.The results show: 1) With the electron beam surface treatment, the surface of sample will re-melting and produce molten pit, both of this two phenomenon have two sides influence on surface roughness; compared to the original sample, the samples with electron beam treatment have some improvements on its hardness and wear-resisting performance. 2) The oxidation dynamic curve show that the high temperature oxidation performance of electron beam alloying samples have improved, but the electron beam surface treatment sample without alloying has not improved its high temperature oxidation performance. With the analysis of surface morphology and XPS, the oxide layer and modified layer of 3Cr2W8V electron beam surface alloying Al sample has better strength and inoxidizability than original sample and electron beam surface treatment sample without alloying. 3) After electron beam surface treatment, the thermal fatigue performance of sample is degrade obviously. We discuss this phenomenon from the roughness, residual stress and surface topography, and improved the traditional experiment scheme.