防止铸钢粘砂的黄壤土型砂性能与工艺研究  

Influence of Sintering Behavior of Natural Clay-bonded Sand on Surface Quality of Steel Castings

作　　者：桑小龙[1,2] 朱世根[1,2] 骆岚[1,2] 高远[1,2] 

机构地区：[1]东华大学机械工程学院,上海201620 [2]东华大学纺织装备教育部工程研究中心,上海201620

出　　处：《机械工程学报》2012年第14期64-69,共6页Journal of Mechanical Engineering

基　　金：国家211工程;'机械制造及其自动化'上海市重点学科建设和国家发改委产业结构调整计划资助项目

摘　　要：运用黄壤土型砂的烧结产生可剥离烧结层,可以有效防止铸钢件表面的粘砂类缺陷,提高铸钢件表面质量。调整黄壤土型砂的石英砂质量分数及粒径,进行不同温度下的烧结试验,研究适合不同温度下烧结的型砂配比。通过模拟烧结层试样的高温与室温力学性能测试,研究烧结层力学性能。依据型砂烧结试验和烧结层力学性能试验结果,将黄壤土和粒径为0.15～0.30 mm(50/100目)石英砂以3∶7配制的黄壤土型砂运用在铸钢件浇注试验,发现砂型与铸件界面产生一层致密的烧结层,并且在室温下可以轻易地从铸件表面剥离,获得表面光洁的铸钢件。研究表明,调整黄壤土型砂的成分可以调节型砂耐火度,使其满足在不同浇注温度下,在铸型—铸件界面处生成适度烧结的烧结层。该烧结层在高温下呈现良好塑性,粘附在铸钢件表面,抵挡金属液的冲刷和渗透;当铸钢件冷却至室温时,烧结层呈现出明显的脆性,可以很容易地剥离铸钢件表面,从而极有可能防止铸钢件的粘砂类缺陷,获得表面质量高的铸钢件。The strippable sinter layer, which is produced during sintefing of natural clay-bonded sand, can eliminate the bum-on defects and improve the surface quality of steel castings. A series of sintering experiments are carried out with different size and weight ratio of silica sands to find a proper formula of molding sand under different sinter temperatures. The molding sand, which is composed of natural clay and diameter 0.15-0.30 mm （50/100 mesh） silica sands with mixing ratio of 3 ： 7, is used in the pouting experiment of steel casting sample. The mechanical performances of natural clay-bonded sand at elevated and room temperatures are also investigated. A compact layer of bum-on sands appeared between the surface of sand mould and steel casting, which is easy to be peeled from the casting surface. The results indicated the moderate sinter layer can be generated under different pouring temperature by changing the components of molding sand; The sinter layer has excellent plasticity at elevated temperature to resist the scouring and infillration of liquid metal. After the liquid metal is solidified, the sinter layer can finrdy adhere to the casting surface. At room temperature, it exhibited obvious brittleness and is easy to be stripped. The steel casting with high surface quality can be acquired after the peeling of sinter layer.

关 键 词：黄壤土型砂 铸钢 烧结层 粘砂 

分 类 号：TG221[金属学及工艺—铸造]