石墨是用焦碳粉和石墨粉或加碳黑做基料，用瀝青為粘結(jié)劑，經(jīng)模壓成型在高溫下燒制而成的。一般將燒結(jié)石分為二種。一種為碳素石墨，以稱碳石墨，其特點(diǎn)是質(zhì)硬、脆；另一種為石墨化石墨，以稱電化石墨，其特點(diǎn)是質(zhì)軟、強(qiáng)度低，自潤滑性能好。

      石墨具有優(yōu)良的耐腐蝕性能。其化學(xué)穩(wěn)定性能很高，在空氣中400℃以下穩(wěn)定，除強(qiáng)氧化性介質(zhì)如王水、鉻酸、濃**及鹵素外，可耐其它酸、堿、鹽類及一切有機(jī)化合物的腐蝕。石墨的耐腐蝕程度一般隨基料的種類和浸漬劑的不同而異。

      石墨是機(jī)械密封摩擦付材料中用量**大，使用范圍**的一種材料。它具有優(yōu)良的耐腐蝕性能，除了強(qiáng)氧化性介質(zhì)外，可以耐各種濃度的酸、堿、鹽類及一切有機(jī)化合物的腐蝕。同特別好的自潤滑性和低的摩擦系數(shù)，與鋼對磨時，摩擦系數(shù)為0.04-0.05，經(jīng)浸漬處理的碳石墨在流體動力潤滑條件下，其摩擦系數(shù)在0.08-0.1范圍內(nèi)。石墨具有很高的導(dǎo)熱系數(shù)(100～110千卡/米·時·度)，較低的線膨脹系數(shù)(2～3×10-6℃)以及良好的耐溫急變性能和加工性能，可以進(jìn)行各種機(jī)械加工。

      Graphite is the widest and most quantity materials used in the machine seal parts. It has a good erode-resistant ability. It can stand against cauterization from acid, alkali, salt and all organic compound except strong oxidation material.

      Because of it's special ideal lubricative ability, the rub coefficient is between with 0.04 and 0.05 when it is rubbed with steel. With dipping treatment, under the situation of hydrokinetics, the rub coefficient is between with 0.08 and 0.10.

      Graphite has a high heat-transmiting coeficient(100～110kilo-calorie/metre hour degree), and a lower line expanding coefficient(2～3×10-6℃), favorable anti-temperature deformationand machining ability. It can be processed by several kings of mechanical means.