復(fù)合井蓋的使用技術(shù)：復(fù)合井蓋在鑄造過程中此普通灰口鑄鐵的白口傾向大，內(nèi)應(yīng)力也較大，復(fù)合井蓋很難得到純粹的鐵素體或珠光體基體，為提高復(fù)合井蓋的延性或韌性，常將復(fù)合井蓋重新加熱到900-950℃并保溫足夠時(shí)間進(jìn)行高溫退火，再爐冷到600℃出爐變冷。過程中基體中的滲碳體分解出石墨，自?shī)W氏體中析出石墨，這些石墨集聚于原球狀石墨周圍，基體全轉(zhuǎn)換為鐵素體。復(fù)合井蓋作為軸類件，如柴油機(jī)的曲軸、連桿，要求強(qiáng)度高同時(shí)韌性較好的綜合機(jī)械械性能，對(duì)復(fù)合井蓋進(jìn)行調(diào)質(zhì)處理。

工藝是：復(fù)合井蓋加熱到860-900℃的溫度保溫讓基體奧氏體化，再在油或熔鹽中冷卻實(shí)現(xiàn)淬火，后經(jīng)500-600℃的高溫回火，獲得回火索氏體組織(一般尚有少量粹塊狀的鐵素體)，原球狀石墨形態(tài)不變。處理后強(qiáng)度，韌性匹配良好，適應(yīng)于軸類件的工作條件。

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.