性能添加剂 - 汽车润滑油

添加剂类型    倾点下降剂
目的                使润滑油在低温下流动

添加剂类型    粘度调节剂
目的                降低粘度随温度变化的速率

添加剂类型   消泡剂
目的                防止润滑剂形成持久性泡沫

添加剂类型   抗氧化剂
目的               延缓氧化分解

添加剂类型   抗磨极压剂
目的               减少摩擦和磨损并防止划伤和咬合

添加剂类型   缓蚀防锈剂
目的               防止与润滑剂接触的金属部件腐蚀和生锈

添加剂类型   洗涤剂
目的               保持表面无沉积物

添加剂类型   分散剂
目的               使不溶性污染物分散在润滑剂中

添加剂类型   摩擦改进剂
目的               改变摩擦系数

润滑油的一般特性
粘度
• 这表示液体流动的阻力。
• 有几种测量粘度的单位。以前，美国常用的单位是 Saybolt Universal Second (SSU)，测量值为 100?/span>F 或 210?/span>F。在欧洲，以前广泛使用的单位是红木 I 秒 (RWI)，测量值为 100?/span>F 或 210?/span>F。目前，大多数国家已改用厘沲（cSt）为单位的公制，在 40?/span>C 或 100?/span>C 下测量。
• 粘度较高的油可以承受更大的压力而不会被挤出润滑表面。然而，油的高内摩擦可能对润滑部件的运动提供更大的阻力。粘度较低的油对运动部件的阻力较小，但油很容易从润滑表面挤出。因此选择合适粘度的润滑油以达到最佳的润滑效果很重要。
• 粘度随温度变化。因此，只要指出液体的粘度，就必须指定测量温度。当温度升高时，液体变得不那么粘稠。同样，当温度下降时，液体会变稠。
• 粘度指数(VI) 表示液体的粘度如何随温度变化。高 VI 意味着当温度升高时液体不会变稀。通常为高分子量聚合物的 VI 改进剂添加剂可以提高润滑油的 VI。
• 通过添加聚合物实现的油粘度增加可能会因剪切应力（如重载齿轮）引起的聚合物分子降解而部分损失。据说可以抵抗剪切引起的粘度变化的油具有高剪切稳定性。

倾点
-表示低温下的流量特性
-取决于油的蜡含量

闪点
-测量油在空气中瞬间点燃的准备情况，并且是关于油的火灾危险的考虑因素.

氧化稳定性
-油的氧化会产生树脂和油泥，可能会堵塞过滤器和油道
-氧化还会产生可溶性有机酸，可能会腐蚀机器零件
-好的润滑油应该是抗氧化的

酸度和碱度（总酸值和总碱值）
-高酸性油可能会导致机器零件腐蚀
-由于添加了清净型添加剂，大多数机油都显示出一定的碱性，这有助于中和机油中因氧化而形成的任何酸
-长期使用后，润滑油可能含有氧化形成的有机酸。因此，测量油的酸度可以反映其氧化程度

去污力
-大多数机油都含有清洁剂和分散剂添加剂，以防止不完全燃烧产生的脏颗粒在金属表面积聚和电镀.

防锈性能
-水可能会渗入润滑系统并导致机器零件生锈
-铁锈颗粒可以作为催化剂加速油的氧化
-防锈添加剂可以吸附在金属表面，防止水分与金属接触，从而防止生锈。

腐蚀抑制
-油中的酸性物质会导致机器零件腐蚀
-可以通过缓蚀剂添加剂将腐蚀降至最低，缓蚀剂与金属反应形成保护层，将酸性材料和金属隔开

消泡性
-起泡会降低油的润滑性，因为泡沫中的气泡会在油和金属表面之间形成屏障
-泡沫还会对机器零件的运动产生阻力
-在液压系统中，泡沫会降低油的内聚力并导致液压下降
-好的润滑油不易起泡，能迅速消泡。消泡剂有助于降低油的起泡倾向

乳化和破乳
-乳化是油和水的均匀混合
-有些油要求乳化性高，容易与水混合，例如一些金属切削油
-通过添加对油和水都有很强亲和力的乳化剂，从而将油和水分子结合在一起，可以提高油的乳化性
-其他一些润滑剂需要良好的抗乳化性，以便水可以很容易地从油中分离出来，例如。涡轮机油。油的抗乳化性可以通过良好的精炼技术来实现

抗磨性能
-某些润滑条件可能需要极轻的油，一种粘度低于机器负载速度关系的油。在这种情况下，可能会发生金属表面的磨损。抗磨添加剂在金属表面形成一层保护涂层，使表面相互滑动，金属损失最小

极压负荷性能（EP）
-重载、极压和高温可能导致机器运动部件熔化并焊接在一起，从而干扰运动
-油中的极压添加剂能与金属反应生成低熔点化合物。由于极压负载而产生的高温将在化合物的熔化过程中消散，而不是将两个金属部件焊接在一起
- EP 特性通常通过 Timken 方法 (ASTM D 2782) 或 FZG Gear Machine (IP 334) 测量。在铁姆肯公司的方法中，钢杯在润滑剂槽中靠着钢块旋转。不会导致得分的最大负载是 OK 负载。在 FZG 齿轮机中，特殊齿轮在被测润滑油中运行。负载分阶段增加，齿轮损坏发生的阶段被报告为润滑剂的 ​​FZG 负载阶段

粘性
-粘性油含有粘性剂，会长期粘附在润滑表面而不会飞溅。用于纺织机械和钢丝绳的润滑剂通常需要粘性。

润滑脂的一般特性

润滑脂是由增稠剂分散在液体润滑剂（基础油）中形成的半固体。可以包括其他赋予特殊性能的成分。在某些应用中，润滑脂优于油，因为润滑脂停留在润滑点，几乎不会被挤出。有时，润滑脂也可用于密封机器部件，以防止水分和灰尘进入。

基础油粘度、碳氢化合物类型和挥发性会影响润滑脂的结构稳定性、润滑质量、低温和高温性能以及成本。增稠剂是控制耐水性、耐高温性能、通过持续使用抗击穿以及保持原位的能力的主要因素。在很大程度上，润滑脂成本取决于增稠剂和其他添加剂的类型。

增稠剂可分为几类；皂型、无机型和合成有机型。

润滑脂的重要特性如下：

渗透
-这表示润滑脂的稠度（硬度或软度）。它是通过将一个尖锥体滴入油脂中并观察锥体穿透样品的深度来测量的。不同的渗透范围由以下国家润滑脂协会 (NLGI) 等级编号确定：000、00、0、1、2、3、4、5 和 6。000 级最软，而 6 级最硬。

-大多数用肥皂增稠的油脂会随着温度的升高而变软，但有些油脂在暴露于高温时会逐渐变硬。总体而言，非皂类增稠剂的稠度随温度升高变化很小。

防水性
-增稠剂溶于水的润滑脂遇水量较大时会发生乳化流化。一般来说，钙皂、锂皂和铝皂的抗水性都很强，而钠皂润滑脂则易溶于水

氧化稳定性
-氧化会导致润滑脂变硬，形成清漆状薄膜并最终碳化。添加剂可以提高润滑脂的氧化安定性

润滑性能
-皂型润滑脂中的油和增稠剂均具有润滑性能。无机非皂类增稠剂一般对润滑脂没有润滑作用。油的润滑能力取决于其粘度和粘度指数

抗磨特性
-润滑脂中可能包含添加剂以提高其抗磨损性能

极压能力（EP）
-一些润滑脂含有特殊添加剂以增强其承载能力，从而可以最大限度地减少金属的焊接和划痕

滴点
-它是润滑脂流动到足以滴落的温度。滴点低于工作温度的润滑脂不能提供合适的润滑剂。但是，反之则不一定成立。高于工作温度的滴点并不能保证足够的润滑，因为在高温下润滑脂的稠度可能会发生变化，化学性质也会变差。

• API Engine Service Classifications

  The American Petroleum Institute (API) engine oil classification system was set up as a joint effort by API, ASTM (American Society for Testing and Materials) and SAE (Society of Automotive Engineers). The letter classification system is a method of classifying engine oils according to their performance characteristics and relating this to their intended type of service.

  The API system currently includes service classifications for service stations/spark ignition engines ("S" series), for commercial application/compression ignition engines ("C" series), and for energy conserving engine oil ("EC" series). It is an "open-ended" system that allows for the addition of new designations with little change to existing ones.

  S Series

  SA – Formerly for Utility Gasoline and Diesel Engine Service (Obsolete) – Category SA denotes service typical of older engines operated under such mild conditions that the protection afforded by compounded oils is not required. This category has no performance requirements, and oils in this category should not be used in any engine unless specifically recommended by the equipment manufacturer.

  SB – Minimum-Duty Gasoline Engine Service (Obsolete) - Category SB denotes service typical of older engines operated under such mild conditions that only minimum protection afforded by compounding is desired. Oils designed for this service have been used since 1930s and provide mild anti-scuff capability and resistance to oil oxidation and bearing corrosion. They should not be used in any engine unless specifically recommended by the equipment manufacturer.

  SC – 1964 Gasoline Engine Service (Obsolete) - Category SB denotes service typical of gasoline engines in 1964 through 1967 models of passenger cars and some trucks, operating under engine manufacturers’ warranties in effect during those model years. Oils designed for this service provide control of high and low temperature deposits, wear, rust, and corrosion in gasoline engines.

  SD – 1968 Gasoline Engine Service (Obsolete) - Category SD denotes service typical of gasoline engines in 1968 through 1970 models of passenger cars and some trucks, operating under engine manufacturers’ warranties in effect during those model years. This category may also apply to certain 1971 or later models as specified (or recommended) in the owners’ manuals. Oils designed for this service provide more protection against high and low temperature deposits, wear, rust, and corrosion in gasoline engines than oils that are satisfactory for API Engine Service Category SC and may be used when API Engine Service Category SC is recommended.

  SE – 1972 Gasoline Engine Service (Obsolete) - Category SE denotes service typical of gasoline engines in passenger cars and some trucks beginning with 1972 and certain 1971 through 1979 models operating under engine manufacturers’ warranties. Oils designed for this service provide more protection against oil oxidation, high temperature deposits, rust, and corrosion in gasoline engines than oils that are satisfactory for API Engine Service Category SD or SC and may be used when either of these categories is recommended.

  SF – 1980 Gasoline Engine Service (Obsolete) - Category SF denotes service typical of gasoline engines in passenger cars and some trucks beginning with 1980 through 1989 models operating under engine manufacturers’ recommended maintenance procedures. Oils developed for this service provide increased oxidation stability and improved antiwear performance relative to oils that meet the minimum requirements of API Service Category SE. These oils also provide protection against engine deposits, rust, and corrosion. Oils meeting API Service Category SF may be used when API Engine Service Category SE, SD or SC are recommended.

  SG – 1989 Gasoline Engine Service (Obsolete) - Category SF denotes service typical of gasoline engines in passenger cars, vans, and light trucks operating under manufacturers’ recommended maintenance procedures. Category SG oils include the performance properties of API Service Category CC. (Certain manufacturers of gasoline engines require oils that also meet the higher diesel engine Category CD.) Oils developed for this service provide improved control of engine deposits, oil oxidation, and engine wear relative to oils developed for previous categories. These oils also provide protection against rust and corrosion. Oils meeting API Service Category SG may be used when API Engine Service Category SF, SE, SF/CC or SE/CC are recommended.

  SH – 1994 Gasoline Engine Service - Category SH was adopted in 1992 to describe engine oil first mandated in 1993. It is for use in service typical of gasoline engines in present and earlier passenger cars, vans, and light trucks operating under manufacturers’ recommended maintenance procedures. Engine Oils developed for this category provide performance exceeding the minimum requirements for API Service Category SG, which it is intended to replace, in the areas of deposit control, oil oxidation, wear, rust, and corrosion. Oils meeting API SH requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SG and earlier categories are recommended. Effective August 1, 1997, API SH cannot be used except with API CF, CF-2, CF-4 or CG-4 when displayed in the API service symbol, and the C category must appear first.

  SJ – 1997 Gasoline Engine Service – Category SJ was adopted in 1996 to describe engine oil first mandated in 1997. It is for use in service typical of gasoline engines in present and earlier passenger cars, vans, and light trucks operating under manufacturers’ recommended maintenance procedures. Oils meeting API SH requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SH and earlier categories are recommended.

  SL – 2001 Gasoline Engine Service – Category SL was adopted to describe engine oils for use in 2001. It is for use in service typical of gasoline engines in present and earlier passenger cars, sports utility vehicles, vans and light trucks operating under vehicle manufacturers’ recommended maintenance procedures. Oils meeting API SL requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SJ and earlier categories are recommended.

  SM - Introduced on 30 November 2004 - Category SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. They may be used where API Service Category SJ and SL earlier categories are recommended.

  SN - Introduced in October 2010, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85.

  C Series

  CA – Diesel Engine Service (Obsolete) – Service typical of diesel engines operated in mild to moderate duty with high quality fuels; occasionally has included gasoline engines in mild service. Oils designed for this service provide protection from bearing corrosion and ring-belt deposits in some naturally aspirated diesel engines when using fuels of such quality that they impose no unusual requirements for wear and deposits protection. They were widely used in the 1940s and 1950s but should not be used in any engine unless specifically recommended by the equipment manufacturer.

  CB – Diesel Engine Service (Obsolete) – Service typical of diesel engines operated in mild to moderate duty, but with lower quality fuels, which necessitate more protection from wear and deposits; occasionally has included gasoline engines in mild service. Oils designed for this service were introduced in 1949. They provide necessary protection from bearing corrosion and from high temperature deposits in naturally aspirated diesel engines with higher sulfur fuels.

  CC – Diesel Engine Service (Obsolete) – Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines operated in moderate to severe-duty service, and certain heavy-duty gasoline engines. Oils designed for this service provide protection from bearing corrosion, rust, corrosion and from high to low temperature deposits in gasoline engines. They were introduced in 1961.

  CD – Diesel Engine Service (Obsolete) – Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines where highly effective control of wear and deposits is vital, or when using fuels with a wide quality range (including high-sulphur fuels). Oils designed for this service were introduced in 1955 and provide protection from high temperature deposits and bearing corrosion in these diesel engines.

  CD-II – Severe-Duty Two-Stroke Cycle Diesel Engine Service (Obsolete) – Service typical of two-stroke cycle diesel engines requiring highly effective control of wear and deposits. Oils designed for this service also meet all performance requirements of API Service Category CD.

  CE – 1983 Diesel Engine Service (Obsolete) – Service typical of certain turbocharged or supercharged heavy-duty diesel engines, manufactured since 1983 and operated under both low speed, high load and high speed, high load conditions. Oils designed for this service may also be used when API Service Category CD is recommended.

  CF-4 – 1990 Diesel Engine Service – Service typical of high speed, four-stroke cycle diesel engines. API CF-4 oils exceed the requirements for the API CE category, providing improved control of oil consumption and piston deposits. These oils should be used in place of API CE oils. They are particularly suited for on-highway, heavy-duty truck applications. When combined with the appropriate “S” category, they can also be used in gasoline and diesel powered personal vehicles – i.e., passenger cars, light trucks and vans – when recommended by the vehicle or engine manufacturer.

  CF – Indirect-Injected Diesel Engine Service – Service typical of indirect-injection diesel engines and other diesel engines that use a broad range of fuel types, including those using fuel with high sulphur content; for example, over 0.5% wt. Effective control of piston deposits, wear and copper-containing bearing corrosion is essential for these engines, which may be naturally aspirated, turbocharged or supercharged. Oils designated for this service have been in existence since 1994 and may be used when API Service Category CD is recommended.

  CF-2 – Severe-Duty Two-Stroke Cycle Diesel Engine Service (Obsolete) – Service typical of two-stroke cycle diesel engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designed for this service have been in existence since 1994 and may be used when API Service Category CD-II is recommended. These oils do not necessarily meet the requirements of API CF or CF-4 unless they pass the test requirements for these categories.

  CG-4 – 1994 Severe-Duty Diesel Engine Service – This category describes oils for use in high speed four-stroke-cycle diesel engines used in both heavy-duty on-highway (0.05% wt sulphur fuel) and off-highway (less than 0.5% wt sulphur fuel) applications. CG-4 oils provide effective control over high temperature piston deposits, wear, corrosion, foaming, oxidation stability, and soot accumulation. These oils are especially effective in engines designed to meet 1994 exhaust emission standards and may also be used in engines requiring API Service Categories CD, CE, and CF-4. Oils designed for this service have been in existence since 1994.

  CH-4 Severe-Duty Diesel Engine Service – This service oils are suitable for high speed, four-stroke diesel engines designed to meet 1998 exhaust emission standards and are specifically compounded for use with diesel fuels ranging in sulphur content up to 0.5% weight. CH-4 oils are superior in performance to those meeting API CF-4 and API CG-4 and can effectively lubricate engines calling for those API Service Categories.

  CI-4 – 2002 – Severe-Duty Diesel Engine Service – The CI-4 performance requirements describe oils for use in those high speed, four-stroke cycle diesel engines designed to meet 2004 exhaust emission standards, to be implemented October 2002. These oils are compounded for use in all applications with diesel fuels ranging in sulphur content up to 0.5% by weight. These oils are especially effective at sustaining engine durability where Exhaust Gas Recirculation (EGR) and other exhaust emission componentry may be used. Optimum protection is provided for control of corrosive wear tendencies, low and high temperature stability, soot handling properties, piston deposit control, valve train wear, oxidative thickening, foaming and viscosity loss due to shear. CI-4 oils are superior in performance to those meeting API CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories.

  CI-4 Plus - 2004 - Used in conjunction with API CI-4, the " CI-4 PLUS" designation identifies oils formulated to provide a higher level of protection against soot-related viscosity increase and viscosity loss due to shear in diesel engines. Like Energy Conserving, CI-4 PLUS appears in the lower portion of the API Service Symbol "Donut."

  CJ-4 – 2006 – Severe-Duty Diesel Engine Service – The CJ-4 performance requirements describe oils for use in those high-speed, four-stroke cycle diesel engines designed to meet 2007 model year on-highway exhaust emission standards. These oils are compounded for use in all applications with diesel fuels ranging in sulphur content up to 0.05% by weight. However, use of these oils with greater than 15 ppm (0.0015% by weight) sulphur fuel may impact exhaust aftertreatment system durability and/or oil drain interval. These oils are especially effective at sustaining engine durability where Exhaust Gas Recirculation (EGR) and other exhaust emission componentry may be used. Optimum protection is provided for control of catalyst poisoning, particulate filter blocking, engine wear, piston deposits, low and high-temperature stability, soot handling properties, oxidative thickening, foaming and viscosity loss due to shear. CJ-4 oils are superior in performance to those meeting API CI-4 with CI-4 Plus, CI-4, CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories.