A new design of copper-bearing non-quenched plastic mold steel is presented and explained. Two kinds of microstrueture can be obtained from this new type copper-bearing steel via cooling with different cooling rates, ...A new design of copper-bearing non-quenched plastic mold steel is presented and explained. Two kinds of microstrueture can be obtained from this new type copper-bearing steel via cooling with different cooling rates, bain- ite and a mixed microstructure consisting of ferrite and bainite. It is found that, after proper tempering process, the hardness will be increased. Moreover, the hardness difference between different microstructures will be reduced. For further investigation, the samples tempered at different temperatures were examined by XRD and 3PAP （three di- mensional atom probe） analysis. Results show that the improvement is contributed mainly by the precipitation of Cu phase and transformation of residual austenite.展开更多
In order to meet the demand of prehardened steel for large section plastic mould and save energy, a nonquenched prehardened （NQP） steel is developed. The temperature field of a large block is researched by finite el...In order to meet the demand of prehardened steel for large section plastic mould and save energy, a nonquenched prehardened （NQP） steel is developed. The temperature field of a large block is researched by finite element method simulation and 9 test steels are designed in the laboratory. Their microstructures and hardness are investigated when they are air cooled and control cooled at cooling rate similar to the simulation. The result shows that the hardness uniformity through section is closely correlated to bainitic hardenability for the NQP steel, and the hardness of one test steel （0.27C-1.95Mn-1.04Cr-0.45Mo-0.1V） fluctuates between HRC 40 and 43 under both cooling conditions. The test steel has better machinability compared with C45 steel, and the NQP steel is produced successfully in the factory based on the laboratory results. Its microstructure is bainite, and it is distributed uniformly through the size of 460 mm×800 mm×3 200 mm.展开更多
基金Sponsored by National Key Technology Research and Development Program in 11th Five-Year Plan of China(2007BAE51B04)
文摘A new design of copper-bearing non-quenched plastic mold steel is presented and explained. Two kinds of microstrueture can be obtained from this new type copper-bearing steel via cooling with different cooling rates, bain- ite and a mixed microstructure consisting of ferrite and bainite. It is found that, after proper tempering process, the hardness will be increased. Moreover, the hardness difference between different microstructures will be reduced. For further investigation, the samples tempered at different temperatures were examined by XRD and 3PAP （three di- mensional atom probe） analysis. Results show that the improvement is contributed mainly by the precipitation of Cu phase and transformation of residual austenite.
基金Item Sponsored by Shanghai Leading Academic Discipline Project (T0101)
文摘In order to meet the demand of prehardened steel for large section plastic mould and save energy, a nonquenched prehardened （NQP） steel is developed. The temperature field of a large block is researched by finite element method simulation and 9 test steels are designed in the laboratory. Their microstructures and hardness are investigated when they are air cooled and control cooled at cooling rate similar to the simulation. The result shows that the hardness uniformity through section is closely correlated to bainitic hardenability for the NQP steel, and the hardness of one test steel （0.27C-1.95Mn-1.04Cr-0.45Mo-0.1V） fluctuates between HRC 40 and 43 under both cooling conditions. The test steel has better machinability compared with C45 steel, and the NQP steel is produced successfully in the factory based on the laboratory results. Its microstructure is bainite, and it is distributed uniformly through the size of 460 mm×800 mm×3 200 mm.
