Hot Forging Die Zone Temperature Fluctuations In The Design And Preparation Of Materials

A long time,die steel homogeneous limitations of the use of performance has seriously hampered the improvement of service life of hot forging dies.Group where the author proposed to alleviate the thermal stress of functionally graded materials (Functionally Gradient Materials FGM) to design and manufacture of hot forging of long-lived mode,thus substantially improve the life of hot forging dies.This article attempts to temperature fluctuations of hot forging die area of the design and manufacture of materials to verify and to achieve the above-mentioned theory.The paper first discusses the main failure mode of hot forging and heat load of the form of repeated mold cavity under the surface may occur in four different forms of reaction(thermal fatigue,phase change and tempering,and plastic deformation), resulting in heat Die Fatigue is the most important conclusions of the failure mode and analysis of the impact of thermal fatigue of several key factors(1.the physical properties of materials;2.the mechanical properties of materials;3.The chemical composition of materials;4.material microstructure).And then focuses on the thermal fatigue crack initiation and expansion of the mechanism.First of all,the second part of the article discusses the long-lived structure of hot forging die material and surface area material layer performance requirements.Area under the surface layer to the performance requirements of materials selection of the most suitable types of hot die steel,and the composition of chemical elements according to their preparation of the welding electrode to prepare the surface layer stack deposited zone modules.After discussion of some of the major alloying element in steel elements of the role and interaction between the deposited metal on the reactor performance(hardness,impact energy,crack length,the wear volume) affect the basis of the ratio of alloying elements in several parameters of the initial determine what the hot die steel alloying elements relatively reasonable ratio;in discussing the physical properties of the material parameters on the forging die the day the impact of combined stresses on the basis of the number of candidates in accordance with hot die steel to determine the parameters of the physical properties of the steel W6Mo5Cr4V2 suitable for hot forging dies as a long-life area of the surface layer of the reference steel material.W6Mo5Cr4V2 steel in accordance with the composition of chemical elements prepared corresponding surfacing electrode(after known as the 6542 electrode). The third part of the article through the surface layer zone of the material one by one of the requirements for analysis to determine whether the developed 6542 electrode is key to the success of the 6542 electrode material to be whether or not the cladding layer has a higher hardness and toughness of high-temperature whether it has good resistance to thermal fatigue properties(heat stability and the stability of the high-temper).Therefore,the design of the red hardness of materials,tempering stability and thermal fatigue performance test to verify layer area surfacing materials performance.By the end of the experimental results of comparison and analysis of the trial 6542 electrode metal cladding layer has a good red hardness and tempering stability and thermal fatigue properties of high temperature hardness and toughness,and basically meet the needs of Hot Forging Die surface layer zone of the performance requirements of materials.Cladding and base metal and the dilution of the role of inter-metal cladding layer makes a good change of gradient performance.