According to the causes,the surface defects can be divided into blister containing non-metallic inclusion,blister without non-metallic inclusion and “raindrop”,“gills”，“mountained”.

不含有非金属夹杂的气囊表面缺陷；由气泡产生的“雨点”状表面缺陷；“鱼鳞”状表面缺陷；“山水画”状表面缺陷。

The surface defect appeared mainly as air bubbles and ferroferric oxide drops which centred around the lower outer - field portion of the stoneware cup.

表观缺陷主要表现为釉泡和氧化铁颗粒,且其集中于杯体下部外侧面。

The coatings composed by the chosen refractory is crackfree in high temperature.The castings using the coatings is free of surface defect and the surface roughness can reach 18 - S.

根据此法选出的耐火材料所组成的涂料在高温急热时不开裂，浇注出的铸件表面无缺陷，表面粗糙度达18-S。