复合井盖的使用技术：复合井盖在铸造过程中此普通灰口铸铁的白口倾向大，内应力也较大，复合井盖很难得到纯粹的铁素体或珠光体基体，为提高复合井盖的延性或韧性，常将复合井盖重新加热到900-950℃并保温足够时间进行高温退火，再炉冷到600℃出炉变冷。过程中基体中的渗碳体分解出石墨，自奥氏体中析出石墨，这些石墨集聚于原球状石墨周围，基体全转换为铁素体。复合井盖作为轴类件，如柴油机的曲轴、连杆，要求强度高同时韧性较好的综合机械械性能，对复合井盖进行调质处理。

工艺是：复合井盖加热到860-900℃的温度保温让基体奥氏体化，再在油或熔盐中冷却实现淬火，后经500-600℃的高温回火，获得回火索氏体组织(一般尚有少量粹块状的铁素体)，原球状石墨形态不变。处理后强度，韧性匹配良好，适应于轴类件的工作条件。

Composite covers the use of technology: the chilling tendency composite covers in the casting process this large ordinary gray cast iron, stress is also larger, composite covers difficult to get pure ferrite or pearlite matrix, in order to improve the ductility of composite covers or toughness, often the composite covers reheated to 900-950 ℃ and holding sufficient time for high-temperature annealing, furnace cooling to 600 ℃ and then baked cold. Over of Matrix cementite decomposition graphite, graphite precipitation in austenite from those stacked on the original graphite spherical graphite around the whole substrate is converted to ferrite. Composite covers a shaft parts, such as diesel engine crankshaft, connecting rod, while requiring high strength toughness

comprehensive mechanical mechanical properties of the composite covers be quenched.

Process are: heating to a temperature of thermal insulation composite covers 860-900 ℃ makes austenite matrix, and then cooled in an oil or molten salt to achieve quenching, tempering after the 500-600 ℃ obtain tempered sorbite (generally there are a few pure massive ferrite), the original spheroidal graphite morphology unchanged. After treatment intensity, toughness match well adapted to the working conditions of the shaft member.