發(fā)布時間：2018-11-27 21:19

【摘要】：球墨鑄鐵是現(xiàn)如今一種廣泛應(yīng)用的金屬結(jié)構(gòu)材料,因為其具有良好的力學(xué)性能,良好的加工性能,而在工業(yè)機械等方面受到廣泛的歡迎。在風(fēng)電材料方面,由于球墨鑄鐵的工作環(huán)境,多為低溫條件,故需要球墨鑄鐵在保持一定的強度同時具有較好的低溫沖擊韌性。此外,在船舶等方面,球墨鑄鐵的應(yīng)用量也比較大,故需要良好的耐腐蝕性能。利用改性超細SiC粉體的高熔點、高模量以及抗氧化性等許多屬性,將其應(yīng)用到鑄造合金強韌化領(lǐng)域。本文主要討論了兩組試樣:一組是未加任何添加劑的五批爐次的附鑄試塊;另一組是同樣條件下,加入經(jīng)過五種不同改性處理的超細SiC粉體的附鑄試塊。對得到的五組加粉與未加粉的試塊進行試驗。采用金相組織觀察、球化等級組織含量檢測、拉伸試驗、布氏硬度檢測、彈性模量檢測、低溫沖擊試驗以及腐蝕浸泡試驗。并進一步討論了不同的改性超細SiC粉體對球墨鑄鐵的金相組織、力學(xué)性能的影響。研究結(jié)果表明:加入不同改性處理的超細SiC粉體后的試樣,其基體組織中鐵素體含量增加,晶粒細化,石墨球分布均勻,形態(tài)圓整而細小,石墨球數(shù)較多,球化率變好,多項性能明顯優(yōu)于未加入陶瓷粉體處理的試樣:抗拉強度增加效果最為明顯的為B號試樣,增加了4.5%;延伸率增加的最為明顯的為D號試樣,增加了19.8%;彈性模量提高最明顯的為A號試樣,增加了9.2%;硬度值變化不大,但是D號試樣的硬度值減小了4.5%;低溫沖擊韌性都得到了提升,其中D號試樣增加效果最為明顯,在常溫、-20℃、-40℃的條件下分別提高了2.5%、10.3%和10%;耐酸和耐堿腐蝕的能力B號試樣明顯增強;總體來看,D號試樣的石墨球最細小且圓整,綜合性能最優(yōu)。
[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，

本文編號：2362065