碳化硅保护套管的性能研究及应用

以碳化硅粉作为基本原料,采用反应烧结法制备出尺寸为φ(130~140)mm×1 500 mm的一端封闭的Si C/C/Si3N4复相陶瓷内加热器保护套管。通过实验模拟内加热器服役环境,测试保护套管切割后各区域密度及显气孔率、抗折强度、抗热震性能和抗锌液侵蚀性能。结果表明:烧结后保护套管的平均密度可以达到2.46 g/cm3,平均抗折强度为61.97 MPa,各区域的密度及抗折强度偏差很小;将保护套管切割后得到的试样条在900℃到室温的条件下热震循环40次后表观无明显裂纹,热震后的残余强度仍可达60 MPa以上,并且不和熔融锌液发生反应,在热浸镀锌领域具有良好的应用前景。

Research on Performance and Application of Silicon Carbide Sheath

The SiC/C/Si3N4 composite ceramic used as immersion heater sheath,which is closed at one end and in size of φ(130～140)mm×1 500 mm,was prepared by reactive sintering method using silicon carbide powder as the basic raw material.The density,apparent porosity,bending strength,thermal shock and corrosion resistances of the sheath were tested.The results showed that the average density of sheath was 2.46 g/cm3 and its average bending strength was 61.97 MPa.Besides,the deviation of its density and bending strength was small.No obvious cracks on the samples obtained after cutting the sheath was observed after 40 times' thermal shock under the condition of 900 ℃ to room temperature and the residual bending strength was still up to 60 MPa or more.The sheath does not react with molten zinc as well.The results show that the sheath has a good application prospect in the field of hot dip galvanized.