TRT叶根防腐涂料的性能研究

Performance Research of TRT Blade Root Anticorrosive Coating

高炉煤气余压透平发电装置(TRT)在运行过程中,叶根密封部位易发生严重腐蚀。采样市售密封胶进行调研,初步筛选出可施工时间为0.25~0.5 h、固化时间大于1 h、耐饱和NH4Cl腐蚀的硅橡胶涂料,通过理化性能、耐腐蚀性和实际附着性测定,对涂料进行适用性评价。研究发现:1)理化性能方面,涂料的表干时间为40 min,实干时间为100 min;湿膜厚度为215μm,干膜厚度为146μm;涂料的不挥发物含量为97%(质量分数)和85%(体积分数);涂料固化后,涂层的柔韧性较好;2)耐腐蚀性方面,将涂料制备成拉伸剪切试样,在100℃的饱和NH4Cl溶液中浸泡30 d后,拉伸剪切试板上硅橡胶涂层的颜色未发生改变,涂层与搭接试板的破坏方式均为附着破坏,拉伸剪切强度由1.13 MPa轻微下降至1.09 MPa;3)实际附着性方面,将涂料涂敷于叶根和榫槽之间,室温固化后将叶根从榫槽中推出,涂层对叶根和榫槽的覆盖率大于80%,可以对金属基材起到较好的保护作用。研究表明,选用的硅橡胶涂料满足TRT的工况要求,可以用作叶根的防腐涂料。

There is easy to suffer severe corrosion on the blade root of blast furnace gas residual pressure turbine power generating system(TRT)during operation.The sealants on the market are surveyed,and a silicone rubber coating whose construction time is between 0.25~0.5 h,curing time is more than 1 h and is resistant to saturated NH4Cl corrosion is primarily selected.The applicability of such a silicone rubber coating is evaluated by analyzing its physical and chemical properties,corrosion resistance and actual adhesion.The study shows that:1)In terms of physical and chemical properties,the surface drying time of the coating is 40 min,and its actual drying time is 100 min;its wet film thickness is 215μm and its dry film thickness is 146μm;the non-volatile content of the coating is 97 wt%and 85 vt%,respectively;the flexibility of the coating is good when it is cured;2)In terms of corrosion resistance,even if the coating is prepared into tensile lap-shear specimens and immersed in saturated NH4Cl solution at 100℃for 30 d,the color of the coating still do not change,the failure method between coating and test board are both adhesion damages,and the tensile shear strength slightly decreases from 1.13 MPa to 1.09 MPa;3)In terms of actual adhesion,if the coating is applied in the blade root and the groove,and then the blade root is pushed out from the groove after the coating is cured at room temperature,the coating could cover 80%of the blade roots surface,which can considerably protect the metal substrate.In conclusion,the selected silicone rubber coating meets the requirements of TRT working conditions and could be used as the anticorrosive coating for the blade roots of TRT.