Troubleshooting: Scab, Burn-on, Misrun

常见缺陷：夹砂、粘砂、浇不足

type:troubleshooting · level:intermediate · material:bronze · material:copper · variant:green-sand · variant:resin-sand · stage:pouring · stage:cleanup

标签：缺陷, 夹砂, 粘砂, 浇不足, 故障排查

①夹砂：湿型表层水分高、浇注过猛→降低水分、加煤粉/淀粉提高表强、平稳浇注。②粘砂：砂粒太粗或耐火度不足→换细砂、型腔刷涂料（石墨/锆英粉）。③浇不足：温度低、浇口细、排气差→提高温度、放大浇口、增排气。系统性解决靠"型砂三性能"（强度/透气/耐火）平衡。

①Scab: high surface moisture, aggressive pour → lower moisture, add seacoal/starch, pour gently. ②Burn-on: coarse or low-refractory sand → finer sand, coat cavity (graphite/zircon). ③Misrun: low temp, thin gate, poor vent → raise temp, enlarge gate, vent more. The systematic fix is balancing the "three sand properties" (strength/permeability/refractoriness). ---