延长球铁铸管管模寿命的措施

Measures to Lengthen Working Life of the Mold Used to Cast Nodular Iron Cast Pipes

介绍了球墨铸铁铸管所用管模的工作条件,以及影响管模寿命的主要因素。管模内表面出现裂纹是管模报废的最主要形式,而形成裂纹的最主要原因是由于温度场相对不均匀而产生的热应力。叙述了维护管模的方法:首先要制订合理的使用制度和做好日常生产维护工作,保持温度场相对稳定,并采取必要的工艺保护。管模的修理方法分为定期修理和恢复性修理。定期修理的工艺过程一般为:表面清理→检查→内壁平打点→内壁磨削→韧性打点→清理备用;恢复性修理的工艺过程大致为:表面清理检查→车去裂纹→预热→焊补→退火→车削→内壁磨削→韧性打点→清理备用。

The working conditions of the pipe mold used to cast nodular iron pipes and factors influencing the working life of the pipe mold were introduced. Cracks occurring on the inner surface of the pipe mold was the main reason causing the pipe mold to be rejected,and the thermal stress produced due to the relatively uneven temperature field was the main reason causing the craeks. The method to maintain the pipe mold was described：First of all,it was must to stipulate rational using regulations and seriously to do the routine maintaining works to keep the temperature field relatively stable,and to adopt necessary process safeguard measures. The repairing methods included periodic repair and restoring repair. The periodie repair process normally was：surface cleaning→checking→dots-type flat knocking the inner wall→inner wall grinding→dotstype toughness knoeking→cleaning to make ready fior use. The restoring repair process was approximately：surface cleaning and checking→turning off the cracks→preheating→welding repair→annealing→turuing cut→inner wall grinding→toughness dots-type knoeking→cleaning to make ready for use.