The Research Of H13 Steel In Organization And Performance On Extrusion Wheel

H13 steel is imported from the United States, Chinese brand is 4Cr5MoSiV1 and performing the standard GB/1299-2000, it is one of the widely used industrial hot-work die steel. Extrusion wheel is the important die of Continuous Extrusion Forming machine,It works under the combination of directions of pressure,thermal stress and friction,so the die material should have high performance requirements in the high temperature. Generally, we chose H13 steel as material in continuous extrusion wheel.In the process of practical production, extrusion wheel happens early failure, the life is unstable. Extrusion wheel which happened early failure severely reduces the production efficiency, increases the cost of production.To solve the phenomenon of early failure occured frequently on extrusion wheel, firstly we should understand its the working environment. Then, find out the main reason leading to invalid from the extrusion wheel failure analysis.And again,study on the material and process, try to formulate the organization standards conforms to the working condition of extrusion wheel.Finally, to optimize the more suitable forging and annealed process.(1) Doing experiment to find out the reason of early failure in extrusion wheel by metallographic analysis,hardness and impact test,SEM ect. The results show that severe banded segregation, eutectic carbides which have large angle and chain distribution, Non-metallic inclusions and the reticular secondary carbides all can become the source of crack, leading to the early failure.(2) Analyse the microstructure and properties of annealed and after heat treatment materials by metallographic analysis,hardness and impact test,SEM ect. Finding out that if the microstructure of annealing state have banded segregation, eutectic carbides, the reticular secondary carbides,ect. These defects can’t eliminate after heat treatment.(3) Banded segregation can be referenced to the standard drawing of NADCA,also can be controlled by GB13299-1991, It can be acceptable when the level is less than or equal to 2. Eutectic carbides can be accepted as long as the boundary is smooth and not present linear distribution,the size is under 10 um. The reticular secondary carbides and spheroidization quality is up to qualified if the level is less than or equal to 2 refer to GB1299-1985. Ferrite is as far as possible the equiaxed grains.(4)Comparing four different forging and after forging heat treatment process,find out the more suitable process for extrusion wheel is that,1200℃high temperature homogenization before forging,initial forging temperature is between 1100℃and 1150℃, final forging temperature is between 850 ℃ and 900 ℃, ultra fining treatment after forging,the spheroidization time is long enough.