改性超细SiC粉体对低温高韧性球墨铸铁组织及性能影响的研究
发布时间：2018-11-27 21:19
【摘要】：球墨铸铁是现如今一种广泛应用的金属结构材料,因为其具有良好的力学性能,良好的加工性能,而在工业机械等方面受到广泛的欢迎。在风电材料方面,由于球墨铸铁的工作环境,多为低温条件,故需要球墨铸铁在保持一定的强度同时具有较好的低温冲击韧性。此外,在船舶等方面,球墨铸铁的应用量也比较大,故需要良好的耐腐蚀性能。利用改性超细SiC粉体的高熔点、高模量以及抗氧化性等许多属性,将其应用到铸造合金强韧化领域。本文主要讨论了两组试样:一组是未加任何添加剂的五批炉次的附铸试块;另一组是同样条件下,加入经过五种不同改性处理的超细SiC粉体的附铸试块。对得到的五组加粉与未加粉的试块进行试验。采用金相组织观察、球化等级组织含量检测、拉伸试验、布氏硬度检测、弹性模量检测、低温冲击试验以及腐蚀浸泡试验。并进一步讨论了不同的改性超细SiC粉体对球墨铸铁的金相组织、力学性能的影响。研究结果表明:加入不同改性处理的超细SiC粉体后的试样,其基体组织中铁素体含量增加,晶粒细化,石墨球分布均匀,形态圆整而细小,石墨球数较多,球化率变好,多项性能明显优于未加入陶瓷粉体处理的试样:抗拉强度增加效果最为明显的为B号试样,增加了4.5%;延伸率增加的最为明显的为D号试样,增加了19.8%;弹性模量提高最明显的为A号试样,增加了9.2%;硬度值变化不大,但是D号试样的硬度值减小了4.5%;低温冲击韧性都得到了提升,其中D号试样增加效果最为明显,在常温、-20℃、-40℃的条件下分别提高了2.5%、10.3%和10%;耐酸和耐碱腐蚀的能力B号试样明显增强;总体来看,D号试样的石墨球最细小且圆整,综合性能最优。
[Abstract]:Ductile iron is a kind of widely used metal structural material nowadays, because of its good mechanical properties and good processability, it is widely welcomed in industrial machinery and so on. In the aspect of wind power materials, due to the working environment of ductile iron, most of them are low temperature conditions, so it is necessary for ductile iron to maintain a certain strength and have good low temperature impact toughness at the same time. In addition, the application of ductile iron in ship is also large, so good corrosion resistance is needed. The modified ultrafine SiC powder has been applied to the field of strengthening and toughening of cast alloys by using the properties of high melting point, high modulus and oxidation resistance. In this paper, two groups of specimens are discussed: one group is a group of five batches of cast-attached test blocks without any additives, the other group is a group of adding five kinds of different modified superfine SiC powder castings under the same conditions. Five groups of powdered and unpowdered samples were tested. Metallographic observation, spheroidization grade tissue content detection, tensile test, Brinell hardness test, elastic modulus test, low temperature impact test and corrosion immersion test were used. The effects of different modified ultrafine SiC powders on the microstructure and mechanical properties of ductile iron were discussed. The results show that the content of ferrite in the matrix of the superfine SiC powder with different modification treatment is increased, the grain size is fine, the distribution of graphite ball is uniform, the shape is round and fine, the number of graphite spheres is more, and the spheroidization rate is better. Many properties were obviously superior to those without ceramic powder treatment. The most obvious effect of tensile strength increase was B sample with 4.5% increase. The most obvious increase of elongation is the number D sample, with an increase of 19.8.The modulus of elasticity increases most obviously in the sample A with 9.2. the hardness value of the sample D has not changed much, but the hardness value of the sample number D has decreased by 4.5. The impact toughness at low temperature was improved, and the increasing effect of D # specimen was the most obvious, at normal temperature, -20 鈩，
本文编号：2362065
[Abstract]:Ductile iron is a kind of widely used metal structural material nowadays, because of its good mechanical properties and good processability, it is widely welcomed in industrial machinery and so on. In the aspect of wind power materials, due to the working environment of ductile iron, most of them are low temperature conditions, so it is necessary for ductile iron to maintain a certain strength and have good low temperature impact toughness at the same time. In addition, the application of ductile iron in ship is also large, so good corrosion resistance is needed. The modified ultrafine SiC powder has been applied to the field of strengthening and toughening of cast alloys by using the properties of high melting point, high modulus and oxidation resistance. In this paper, two groups of specimens are discussed: one group is a group of five batches of cast-attached test blocks without any additives, the other group is a group of adding five kinds of different modified superfine SiC powder castings under the same conditions. Five groups of powdered and unpowdered samples were tested. Metallographic observation, spheroidization grade tissue content detection, tensile test, Brinell hardness test, elastic modulus test, low temperature impact test and corrosion immersion test were used. The effects of different modified ultrafine SiC powders on the microstructure and mechanical properties of ductile iron were discussed. The results show that the content of ferrite in the matrix of the superfine SiC powder with different modification treatment is increased, the grain size is fine, the distribution of graphite ball is uniform, the shape is round and fine, the number of graphite spheres is more, and the spheroidization rate is better. Many properties were obviously superior to those without ceramic powder treatment. The most obvious effect of tensile strength increase was B sample with 4.5% increase. The most obvious increase of elongation is the number D sample, with an increase of 19.8.The modulus of elasticity increases most obviously in the sample A with 9.2. the hardness value of the sample D has not changed much, but the hardness value of the sample number D has decreased by 4.5. The impact toughness at low temperature was improved, and the increasing effect of D # specimen was the most obvious, at normal temperature, -20 鈩，
本文编号：2362065
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