水煤浆喷嘴抗热冲击性研究

Coal-water-slurry Nozzle Thermal Shock Resistance Evaluation

用Al2O3/TiC陶瓷和YG8硬质合金材料制备水煤浆喷嘴,通过有限元计算及水淬试验对其抗热冲击性能进行了研究。仿真结果表明:急冷过程中YG8硬质合金产生的热应力小于Al2O3/TiC陶瓷;热应力在2-3s之间达到最大值,10s后趋于稳定;端面热应力沿径向的分布呈现出内孔边缘处最大,外圆柱面次之,中间部分最小。水淬试验中,两种材料表现出不同的失效形式,Al2O3/TiC陶瓷材料主要失效形式是整体开裂;YG8硬质合金材料主要失效形式是局部块状脱落。

Nozzles for coal water slurry （CWS） were made of YG8 cemented carbides and Alumina Ceramic Composites. Their thermal shock resistances were studied by finite element calculation and water quench test. Simulation results show that：YG8 cemented carbides thermal stress in the quenching process is iess than the A1203/TiC composite ceramics; Thermal stress reaches its maximum between 2 -3 seconds and stabilize after about 10 seconds;Thermal stress distribution along the radial direction showing the largest in the edge of the hole, followed by the outer cylinder and minimum in the middle part of the terminal face. The two materials showed different forms of failure in the water quench test, the main fail- ure mode of A1203/TiC ceramic materials is the overall cracking;But YG8 cemented carbides is a partial block off.