【作者】 郭晓燕；

【导师】 徐学明； 陈荣发；

【作者基本信息】 江南大学 ， 食品工程系， 2009， 硕士

【摘要】 颗粒机广泛用于饲料成套工艺,环模是颗粒机的核心部件,环模的使用寿命、性能的优劣直接影响饲料厂家的经济效益,影响环模性能的除原材料、机加工工艺外,主要取决于其热处理工艺,市场环模热处理有普通油淬处理和真空气淬处理。真空气淬具有无氧化、表面光洁度好、变形量小等特点,在模具热处理领域有着广泛的应用前景。为了探索真空气淬对4Cr13环模耐磨性能的影响规律,本文通过普通油淬热处理和真空气淬热处理方法的对比实验,深入系统的研究了机械性能及耐磨性能的变化规律,并利用现代分析方法对不同工艺处理后的试样进行了详细分析与评价,完成的主要工作及取得的主要成果如下:1、详细观察了环模失效的宏观断口形貌,分析了4Cr13不锈钢磨损断裂的几种典型形式及机理,为改善环模的耐磨性能提供了重要的理论指导。2、对真空热处理升温冷却特性、不同淬火介质对表面光沽度的影响、真空淬火对材料综合力学性能的提高进行了详细分析,为进一步优化真空气淬工艺具有一定的指导意义。3、对6.0VVPT-EH-50/50型真空淬火炉及RX2-50-13型普通中高温箱式炉的特点及参数进行了对比分析,为保证真空气淬工艺的稳定性提供了硬件条件,同时考虑了环模的炉内摆放结构,实现了环模变形量小,受热均匀等热处理效果。4、设计了磨损试样、冲击试样、拉伸试样和拉伸试样的夹具,并运用统计分析法对热处理试样进行了准确分析。5、对真空气淬和普通油淬试样的硬度、耐磨性、拉伸性能及冲击性能进行了综合测试。结果表明:普通油淬的环模硬度为HRC51.2、试样的抗拉强度为1000MPa、冲击功为5.12J;真空气淬环模硬度为HRC52.8,试样的抗拉强度为1283Mpa,断冲击功为10J。6、通过相同载荷不同时间和相同时间不同载荷两组耐磨性能对比实验,结果显示:真空气淬由于内部组织相对细小,分布比较均匀,其耐磨性相比普通油淬可以提高20%～50%,使环模耐磨损寿命得到明显提高。更多还原

【Abstract】 Vacuum air quenching have no oxidation, surface finish, and the characteristics of a small amount of deformation, so it has broad application prospects in the field of mold heat treatment. In order to explore the vacuum air quenching 4Cr13 ring die on the effect of the law of resistance, the article discusses about the differences between quenching heat treatment by ordinary oil and vacuum air quenching, the changes of the resistance are investigated in detail by modern analytical methods, The main research work done and the results obtained in this dissertation are as follows:1. The typical macro- fracture surfaces of stainless steel wear 4Crl 3 ring die are observed in detail, and the wear mechanism is also discussed, which provide an important theoretical guidance to improve the resistance of ring die.2. The characteristics of raising temperature and the cooling down are investigated; effects of different quenching medium on surface finish are also studied, and on improving mechanical properties of materials are analyzed in detail.3. The characteristics and parameters of the vacuum quenching furnace typed 6.0VVPT-EH-50/50 and ordinary box-type furnace RX2-50-13 are analyzed, which provide hardware conditions of the stability of vacuum air quenching .In the meantime, the display of ring die in the furnace, the deformation and the temperature uniform are discussed.4. The samples of the wear and tear, impact and tensile specimens are made and analysis is carried by modern analytical methods.5. Hardness, abrasion resistance, tensile properties and impact properties are tested, the results indicated the oil-quenched values are HRC51.2; tensile strength of 1000MPa; impact energy is 5.12J, and the vacuum air- quenched values are HRC52.8, tensile strength of 1283Mpa, impact energy is 10J.6. Two different experiments are investigated at the conditions of the same load and different times, the same time and different load. Small-sized distributed internal organization and high wear-resistances are obtained. The effective life of ring die increased by 20% to 50%.更多还原