Rolling contact fatigue(RCF)properties of SAE 8620 steel after case carburizing have been investigated under two contact stresses of 4.0and 5.5GPa.Results show that the RCF life ranges from 2.5×10^6 to 3×1...Rolling contact fatigue(RCF)properties of SAE 8620 steel after case carburizing have been investigated under two contact stresses of 4.0and 5.5GPa.Results show that the RCF life ranges from 2.5×10^6 to 3×10^7 cycles under the contact stress of 5.5GPa,while it can be more than 1×10^8 cycles under the contact stress of 4.0GPa.The rated fatigue life L_(10)(lives with the 10%failure)is also drastically shortened from 9.8×10^6 to 5.4×10^5 cycles when the contact stress is increased from 4.0to 5.5GPa.Theoretical calculations and fractographs show that the maximum shear stress and the contact area increase with increasing the contact stress,making RCF tend to occur earlier.展开更多
Steel is the dominant construction material for most industrial goods such as equipments, structures, buildings or vehicles. Although there have been great advances in steel technology over the last 4 decades, the ind...Steel is the dominant construction material for most industrial goods such as equipments, structures, buildings or vehicles. Although there have been great advances in steel technology over the last 4 decades, the industry currently faces serious sustainability challenges with regard to energy conservation, reduction of CO2 emission and a generally more efficient use of resources. The principal connotation in this respect is increasing steel strength allowing to reduce component weight. However, it is also necessary considering in how far the modified steel properties interfere with typical manufacturing techniques established in the processing chain. A feasible method in this sense is a reverse approach starting from detailed knowledge of the manufacturing process and translating it back into the most suitable metallurgical and microstruc- tural design of steel. Modifying steels towards better manufacturing performance typically involves innovative alloying and metallurgical processing concepts. Niobium and molybdenum are two of the most powerful alloying elements in helping to adapt microstructures and properties with regard to downstream manufacturing processes. This paper will highlight several examples how a reverse met- allurgical engineering approach can be successfully applied to optimize the efficiency of subsequent manufacturing processes with a focus on the automotive industry.展开更多
基金Item Sponsored by National Natural Science Foundation for Youth of China(51301042)
文摘Rolling contact fatigue(RCF)properties of SAE 8620 steel after case carburizing have been investigated under two contact stresses of 4.0and 5.5GPa.Results show that the RCF life ranges from 2.5×10^6 to 3×10^7 cycles under the contact stress of 5.5GPa,while it can be more than 1×10^8 cycles under the contact stress of 4.0GPa.The rated fatigue life L_(10)(lives with the 10%failure)is also drastically shortened from 9.8×10^6 to 5.4×10^5 cycles when the contact stress is increased from 4.0to 5.5GPa.Theoretical calculations and fractographs show that the maximum shear stress and the contact area increase with increasing the contact stress,making RCF tend to occur earlier.
文摘Steel is the dominant construction material for most industrial goods such as equipments, structures, buildings or vehicles. Although there have been great advances in steel technology over the last 4 decades, the industry currently faces serious sustainability challenges with regard to energy conservation, reduction of CO2 emission and a generally more efficient use of resources. The principal connotation in this respect is increasing steel strength allowing to reduce component weight. However, it is also necessary considering in how far the modified steel properties interfere with typical manufacturing techniques established in the processing chain. A feasible method in this sense is a reverse approach starting from detailed knowledge of the manufacturing process and translating it back into the most suitable metallurgical and microstruc- tural design of steel. Modifying steels towards better manufacturing performance typically involves innovative alloying and metallurgical processing concepts. Niobium and molybdenum are two of the most powerful alloying elements in helping to adapt microstructures and properties with regard to downstream manufacturing processes. This paper will highlight several examples how a reverse met- allurgical engineering approach can be successfully applied to optimize the efficiency of subsequent manufacturing processes with a focus on the automotive industry.