双金属液—液复合耐磨锤头的研究与开发

发布时间：2018-03-01 23:27

  本文关键词： 双金属 液液复合 耐磨性 锤头 冶金结合　出处：《河南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：锤式破碎机广泛应用于矿山、水泥、冶金、电力、耐火材料、玻璃及化工等行业破碎物料,锤头(或板锤)的磨损十分严重,少则数天,多则数月便要更换一幅锤头,造成大量的人力物力的浪费,因此提高锤头的耐磨寿命受到用户的普遍关注。本论文研究开发了双金属液液复合技术,应用于高耐磨、较高韧性和低成本的耐磨产品的铸造生产,不仅保证了锤头良好的耐磨性,又大幅度提高了锤头的抗冲击能力。采用砂型铸造方法生产液-液双金属复合锤头和板锤,耐磨层采用高铬铸铁Cr20,垫层采用具有高强韧性的35CrMo低合金钢。锤头复合工艺铸造时,锤柄朝下,锤头朝上,先定量浇注低合金钢锤柄,经过适当的停留后再浇注高铬铸铁耐磨层,两层金属之间实现良好的冶金结合。板锤复合工艺铸造时,板锤的两个耐磨面朝外,分三层浇注,最下边一层是高铬铸铁耐磨层,第二层是低合金钢垫层,最上边一层是高铬铸铁耐磨层,三层依次定量定时浇入,各层之间形成良好的冶金结合。两种金属液均采取变质处理,一方面改善高铬铸铁的碳化物形态与分布;另一方面细化低合金钢的晶粒度,防止低合金钢在高温热处理时晶粒过分长大。液液复合锤头采用加热到950-980℃,然后空冷的热处理工艺,使耐磨层处于淬火状态,具有高硬度、高耐磨性;使背层处于正火状态,保持足够的强韧性。复合锤头的主要技术指标如下:(1)高铬铸铁耐磨部位硬度HRC≥58,韧性ak≥7J/cm2。(2)双金属复合体的耐磨性和使用寿命是高锰钢的2.5-5倍。比整体高铬铸铁锤头的韧性高,成本低。双金属液-液复合锤头的创新性主要体现在:(1)采用无箱组芯造型工艺铸造复合锤头,生产效率高,可操作性强;(2)板锤率先采用了双液三次浇注复合工艺,突破了板锤难以复合的技术难题;(3)复合板锤采用两种金属共用一个浇道新工艺。创新了锤头的双液浇注,促使复合锤头的质量有了进一步提高;(4)两种金属实现了良好的冶金结合,界面强度高,是液固复合的1.3-1.5倍;(5)大幅度降低贵重金属消耗,降低生产成本约30%左右。
[Abstract]:Hammer crusher is widely used in mining, cement, metallurgy, electric power, refractory, glass and chemical industries. The wear of hammer head (or plate hammer) is very serious. In a few days or months, a hammer head needs to be replaced. This paper studies and develops the bimetallic liquid liquid composite technology, which is applied to high wear resistance. The casting production of wear-resistant products with high toughness and low cost not only ensures the good wear resistance of the hammer, but also greatly improves the impact resistance of the hammer. The wear resistant layer is made of high chromium cast iron Cr20, and the cushion layer is 35CrMo low alloy steel with high strength and toughness. After a proper stay, the wear resistant layer of high chromium cast iron is poured, and a good metallurgical combination is realized between the two layers of metal. During the casting of the plate hammer composite process, the two wear-resistant surfaces of the plate hammer are cast outwards, divided into three layers, and the lowest layer is a wear-resistant layer of high chromium cast iron. The second layer is low alloy steel cushion, the top layer is high chromium cast iron wear-resistant layer, three layers are poured in quantitatively and regularly, and good metallurgical combination is formed between each layer. Both kinds of molten metal are modified. On the one hand, the carbides morphology and distribution of high chromium cast iron are improved; on the other hand, the grain size of low alloy steel is refined to prevent it from overgrowing during high temperature heat treatment. The liquid-liquid composite hammer is heated to 950-980 鈩，

本文编号：1554069