Overview
Extreme Pressure (EP) additives are critical components in modern lubricants, designed to protect mechanical systems under severe operating conditions. These chemicals react with metal surfaces to form a sacrificial layer that prevents welding and scoring when normal hydrodynamic lubrication fails. The technology originated in the 1930s to meet the demands of automotive hypoid gears and has since evolved with advanced sulfur, phosphorus, and chlorine-based chemistries. EP additives work by chemically reacting with metal surfaces under high pressure and temperature, creating a low-shear-strength film that reduces friction and wear. They are classified as either active (reacting below 200°C) or passive (requiring higher temperatures), with selection depending on the specific application's thermal regime.
Physical and Chemical Properties
EP additives exhibit diverse properties based on their chemical composition. Sulfur-based additives (e.g., sulfurized olefins) typically appear as amber liquids with densities around 1.1 g/cm³, offering excellent performance in high-temperature gear applications. Phosphorus-containing variants often come as clear liquids or solids with superior anti-wear characteristics but lower extreme pressure thresholds. These compounds demonstrate selective reactivity – remaining inert at ambient temperatures but rapidly forming metal sulfides or phosphides when localized hot spots occur. Their solubility in mineral and synthetic base oils is critical for uniform performance, with modern formulations achieving stability across a wide viscosity range from ISO VG 68 to 460 industrial oils.
Main Applications
The primary use of EP additives is in heavy-duty gear oils for mining equipment, wind turbines, and automotive differentials where contact pressures exceed 1 GPa. In metalworking, they prevent galling during machining of tough alloys – sulfurized types dominate in cutting fluids for stainless steel, while chlorine-based variants excel in aluminum forming operations. Industrial applications extend to wire rope lubricants, compressor oils, and food-grade machinery lubricants (using specially approved chemistries). The global shift toward wind energy has driven demand for advanced EP additives that can withstand the micropitting challenges in turbine gearboxes while maintaining compatibility with biodegradable base oils.
Safety and Storage
Handling EP additives requires precautions due to their reactive nature. Sulfur and phosphorus compounds may cause skin irritation, necessitating nitrile gloves and eye protection during handling. Chlorinated additives require special disposal considerations due to potential dioxin formation during combustion. Storage should be in sealed containers away from strong oxidizers at temperatures below 40°C. Bulk storage tanks require nitrogen blanketing for sulfur-based additives to prevent oxidation. Shelf life typically ranges 1-2 years when properly stored, with viscosity increase being the primary degradation indicator.
B2B Procurement Guide
When sourcing EP additives, verify the supplier's technical support capabilities and request FZG or Timken test data. Key specifications to evaluate include the additive's load-carrying capacity (measured by Four-Ball EP test), thermal stability, and compatibility with your base oil system. For sustainable procurement, inquire about REACH compliance and bioaccumulation potential. Consider ordering small test batches for performance evaluation before large-scale purchases. Leading manufacturers often provide customized formulations for specific equipment types or operating conditions.
Related Manufacturers
- 主营：润湿剂、上光油、除臭剂、极压磨削防锈切削液、拼板胶、消泡剂、乳化剂、引发剂、偶联剂、粘乳液、吊白粉、工业涂料、防水光油、聚乙烯蜡、水性哑油、缩水甘油酯、多功能助剂、高光蜡乳液、自交联单体、网格布乳液、漂白助染剂、酸碱中和剂、乳液还原剂、水性胶粘剂、除臭还原剂、纳米除油乳
- 主营：防冻液、冰醋酸、乙二醇、油性拉拔轧制极压剂、冰乙酸、纯吡啶、丙二醇、羟基苯、14丁二醇、3-丙三醇、四氢呋喃、环保乙腈、化工苯酚、1.4丁二醇、医用苯酚、工业苯酚、精制苯酚、价位四氢、乙腈工业、乙酸乙酯、吡啶化工、甲酸乙酯、吡啶工业、求购苯酚、高纯三氯、实验乙腈
- 主营：异辛醇、乳化剂、乙烯醚、醚羧酸、脂肪醇、分散剂、染色助剂、聚乙二醇、异构醇醚、泊洛沙姆、椰油酰胺、基羟乙基、烷基糖苷、特辛基酚、聚氧乙烯、嵌段聚醚、单油酸酯、异构十三醇、丙烯磺酸钠、氢化蓖麻油、丙烯酰胺基、醇醚葡糖苷、低泡渗透剂、甲酯乙氧基、癸基葡糖苷
- 主营：抗氧剂、乳化剂、苯扎氯铵、极压添加剂、烷基二甲基、氢化蓖麻油、表面活性剂、双链季胺盐、聚氧乙烯醚、二丁基羟基甲苯、甘油聚氧丙烯醚、十二烷基硫酸钠、树脂、助剂
- 主营：摘锭润滑脂、农田防风固沙剂、工程机械专用润滑脂、铁路道钉防护脂、窑车专用润滑脂、纺织机专用脂、特高温脂、颗粒机专用高温脂、半液体锂基润滑脂、高温润滑脂
- 主营：轴承脂、锂基脂、液压油、链条油、bem41-141、润滑剂、导轨油、齿轮油、装配膏、切削油、乳化液、润滑油、润滑脂、防锈油、轴承润滑、万向节脂、针织机油、装配油膏、造纸机油、强力喷剂
- 主营：特种润滑油脂、克鲁勃、摩力克、THK油脂
- 主营：锚固剂、硫酸铝、硫酸铜、切削液、氧化铜、溴化钠、大苏打、导热油、腐植酸、净洗剂、活性炭、水杨酸、硫酸锰、漂白粉、玻璃粉、茶皂素、丁酸钠、磷酸钙、甲酸钠、硬脂酸、消泡剂、酵母硒、磷酸铁、铵明矾、硫酸钡
- 主营：福美钠
- 主营：白炭黑、白僵菌、eva乳液、硫化异丁烯极压抗磨剂、棕榈蜡、pvc发泡剂、聚碳酸酯、聚乙烯蜡、苯甲酸铵、t-31固化剂
- 主营：长效防护润滑脂、汽轮机油、循环润滑油、极压润滑脂、液压油、船舶用油、导轨油、导热油、抗磨润滑脂、工业润滑脂、工业齿轮油、气缸润滑油、抗氧化润滑油、长效防护润滑油、变压器润滑油、绝缘冷却油、抗磨液压油、长效液压油、低温抗磨液压油、耐低温液压油、工业液压润滑油、高性能液压油、车辆齿轮油、环保型变压器油、高温开式齿轮油
- 主营：优氯净、甘氨酸、切削液、水杨酸、硫酸锰、平平加、滑石粉、牛磺酸、白僵菌、磷酸铁、铵明矾、蛋白胨、碳酸镁、磷酸铝、戊二醛、纤维素、硫化钠、硫化钡、黄蜂蜡、硫化钙、氯化锌、氯化锰、氧化锑、氧化锆、氧化锌
- 主营：优氯净、甘氨酸、磷酸硼、水杨酸、硫酸锰、苯甲醇、平平加、正辛烷、一乙胺、磷酸氢、白僵菌、蛋白胨、碳酸镁、磷酸铝、异丁酸、叔丁醇、硫化钡、木质素、醋酸钡、硫化钙、氯化锌、黄原胶、磺酸钙、氟化镁、异丙醇
- 主营：公路工程试验检测仪器、沥青试验仪器、混凝土试验仪器、抗磨极压性能试验机、水泥检测仪器、砂浆试验仪器、建筑材料检测仪器、水利工程检测仪器、质检中心检测仪器、中心实验室仪器设备、防水卷材检测仪器、土工合成材料检测仪器、土工试验仪器、土壤检测仪器
- 主营：抗磨液压油、液力传动油、航空液压油、极压锂基润滑脂、工业齿轮油、汽轮机油、导热油、液压导轨油、真空泵油、空气压缩机油、变压器油、冷冻机油、柴油机油、汽油机油、车辆齿轮油、防冻液、通用锂基润滑脂、二硫化钼、白色特种脂、高温润滑脂、低温润滑脂、汽车制动液、车用尿素、天工抗磨液压油、低温液压油