Core rod lubrication

Poor lubrication effect on mandrel or excessively low temperature of the mandrel lubricant can cause internal scabbing. To increase the mandrel temperature, a single cooling water cooling method can be adopted. The temperature of the mandrel must be strictly controlled during production to ensure that the surface temperature is between 80-120°C before applying the lubricant coating. The mandrel temperature should not remain above 120°C for extended periods to ensure that the lubricant on its surface dries and becomes dense before pre-piercing. Operators should frequently check the lubrication condition of the mandrel.