To provide a grease composition that is capable of effectively preventing an early-flaking caused by hydrogen embrittlement, and a grease-sealed bearing in which the grease composition is sealed. A grease composition 7 contains a base oil, a thickener, and an additive. The additive contains sodium molybdate, and zinc alkyldithiophosphate having a 1-30 C primary alkyl group. The grease composition contains 0.1-5 mass % of the sodium molybdate relative to the whole of the grease composition. The grease composition contains 0.1-5 mass % of the zinc alkyldithiophosphate relative to the whole of the grease composition.

The invention provides a grease composition for a speed reducer part of an on-vehicle electric component, the grease composition containing a base oil and a thickener, wherein the base oil is poly-α-olefin or a mixed oil of poly-α-olefin and mineral oil having a kinematic viscosity of 4 to 19 mm.sup.2/s at 100° C. and a pour point of −30° C. or lower, the thickener is a mixture of a diurea compound expressed by formula (1) and a diurea compound expressed by formula (2)

R.sub.1—NHCONH—R.sub.2—NHCONH—R.sub.1  (1)

R.sub.3—NHCONH—R.sub.2—NHCONH—R.sub.3  (2)

wherein R.sub.1 is a straight-chain alkyl group having 8 or 18 carbon atoms, R.sub.2 is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and R.sub.3 is an aryl group having 6 to 7 carbon atoms, and a penetration of the grease composition is 220 to 280.

The invention provides a grease composition for a speed reducer part of an on-vehicle electric component, the grease composition containing a base oil and a thickener, wherein the base oil is poly-α-olefin or a mixed oil of poly-α-olefin and mineral oil having a kinematic viscosity of 4 to 19 mm.sup.2/s at 100° C. and a pour point of −30° C. or lower, the thickener is a mixture of a diurea compound expressed by formula (1) and a diurea compound expressed by formula (2)

R.sub.1—NHCONH—R.sub.2—NHCONH—R.sub.1  (1)

R.sub.3—NHCONH—R.sub.2—NHCONH—R.sub.3  (2)

wherein R.sub.1 is a straight-chain alkyl group having 8 or 18 carbon atoms, R.sub.2 is a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms, and R.sub.3 is an aryl group having 6 to 7 carbon atoms, and a penetration of the grease composition is 220 to 280.

A grease composition may contain a base oil (A) and a urea-based thickener (B). Particles containing the urea-based thickener (B) in the grease composition may satisfy requirement (I). The base oil (A) may be a mixed base oil containing a high-viscosity base oil (A1) having a kinematic viscosity at 40° C. of 250 mm.sup.2/s to 550 mm.sup.2/s, a low-viscosity base oil (A2) having a kinematic viscosity at 40° C. of 5.0 mm.sup.2/s to 110 mm.sup.2/s, and an ultra-high viscosity hydrocarbon-based synthetic oil (A3) having a number average molecular weight (Mn) of 2,500 to 4,500 and a kinematic viscosity at 40° C. of 25,000 mm.sup.2/s to 50,000 mm.sup.2/s. The base oil (A) may have a kinematic viscosity at 40° C. of 25 mm.sup.2/s to 105 mm.sup.2/s and a viscosity index of 120 or more. Both low-temperature characteristics and a lubricating life can be achieved.

A grease composition may contain a base oil (A) and a urea-based thickener (B). Particles containing the urea-based thickener (B) in the grease composition may satisfy requirement (I). The base oil (A) may be a mixed base oil containing a high-viscosity base oil (A1) having a kinematic viscosity at 40° C. of 250 mm.sup.2/s to 550 mm.sup.2/s, a low-viscosity base oil (A2) having a kinematic viscosity at 40° C. of 5.0 mm.sup.2/s to 110 mm.sup.2/s, and an ultra-high viscosity hydrocarbon-based synthetic oil (A3) having a number average molecular weight (Mn) of 2,500 to 4,500 and a kinematic viscosity at 40° C. of 25,000 mm.sup.2/s to 50,000 mm.sup.2/s. The base oil (A) may have a kinematic viscosity at 40° C. of 25 mm.sup.2/s to 105 mm.sup.2/s and a viscosity index of 120 or more. Both low-temperature characteristics and a lubricating life can be achieved.

A dry film lubricant composition includes: an anionic wax emulsion including carnauba wax and an anionic surfactant; water; a thickener; an organic solvent; a fluorosurfactant; a phosphate additive; and an alkaline agent.

A dry film lubricant composition includes: an anionic wax emulsion including carnauba wax and an anionic surfactant; water; a thickener; an organic solvent; a fluorosurfactant; a phosphate additive; and an alkaline agent.

Disclosed herein is a method for pretreatment of a metallic substrate for a subsequent metal cold forming process, said method , and contacting at least one surface of the substrate with an aqueous lubricant composition (B). The aqueous lubricant composition (B) has a pH value in the range of from 0.1 to 6.0, and includes water in an amount of at least 40 wt.-%, based on the total weight of the composition (B), at least one film-forming polymer, at least one wax, at least one corrosion inhibitor , and oxalate and/or phosphate anions. Further disclosed herein are a pretreated metallic substrate obtainable by the aforementioned inventive method, a method of cold forming of a metallic substrate including a step of subjecting the inventive pretreated metallic substrate to a cold forming process, an aqueous lubricant composition (B), and a master batch for preparing the aqueous composition (B).

Disclosed herein is a method for pretreatment of a metallic substrate for a subsequent metal cold forming process, said method , and contacting at least one surface of the substrate with an aqueous lubricant composition (B). The aqueous lubricant composition (B) has a pH value in the range of from 0.1 to 6.0, and includes water in an amount of at least 40 wt.-%, based on the total weight of the composition (B), at least one film-forming polymer, at least one wax, at least one corrosion inhibitor , and oxalate and/or phosphate anions. Further disclosed herein are a pretreated metallic substrate obtainable by the aforementioned inventive method, a method of cold forming of a metallic substrate including a step of subjecting the inventive pretreated metallic substrate to a cold forming process, an aqueous lubricant composition (B), and a master batch for preparing the aqueous composition (B).

Provided is an engine oil lubricant composition with improved fuel efficiency. The engine oil lubricant composition may include: a polyalpha olefin base oil component an amount of about 50 wt % to about 90 wt % based on a total weight of the engine oil lubricant composition, wherein the polyalpha olefin base oil component is a Group IV base oil and has a Noack volatility of about 12.5% to about 15%; a Group II base oil component in an amount of about 0.1 wt % to about 50 wt % based on the total weight of the engine oil lubricant composition. The engine oil lubricant composition may have (i) a kinematic viscosity at 100° C. of about 10 cSt or less, (ii) a high temperature high shear viscosity at 150° C. of about 2.2 cP or less, and (iii) a Noack volatility of about 20% or less.