摘要
对采用呋喃树脂自硬铬矿砂生产高铬不锈钢水轮机叶片铸件表面易出现"釉化"涂料层、界面型砂"釉化"烧结和粘砂缺陷进行了研究,并提出了解决措施。铸件粘砂的主要原因为钢液透过涂料层渗入铬矿砂,在界面发生氧化还原反应,将铬铁矿砂的铁还原出来,还原出的铁和砂粒形成致密混合物,并附着在铸件表面形成"釉化"烧结层。还原出的铁和铬渣以及砂粒中的未反应物,形成了致密的机械混合物,和铸件金属直接相连,附着在铸件的表面,形成粘砂。锆英粉涂料本身也和高铬钢发生微弱的化学反应。用新型添加剂及复合涂料改进型砂和替代锆英粉涂料,提高了钢液和铬矿砂界面涂料层的致密度、化学稳定性和耐火性,可以有效地解决这类问题。
Some defects such as coating glazing,interface sand glazing and sintering and sand fusion always appear on surface of cast high-chromium stainless steel hydraulic turbine blade castings when using furan resin chromite sand.The main reason for these defects is the infiltration of liquid steel through the coating to chromite and the redox reaction took place which reduces iron out of chromite sand.First,the iron and sand are mixed together and become dense mixture,and then iron,sand and the un-reacted material in sand are mixed together to form dense mechanical mixtures attached to the surface of casting causing the sand burning.Second,a weak chemical reaction occurs between zircon powder coating and the high-chromium steel.According to the analyses,the powder coating with higher chemical stability and fire resistance was chosen instead of zircon powder coating.Additionally,the corundum powder coating can improve the coasting density at the interface of the molten steel and chromite sand.And this method is useful for solving such kind of problems.
出处
《铸造技术》
CAS
北大核心
2011年第5期610-614,共5页
Foundry Technology
关键词
铬铁矿砂
粘砂
“釉化”烧结层
涂料
粘砂烧结机理
Chromite sand
Sand burning
＂Glazing＂defects
Coating
Mechanisms of burning-on
