An anti-corrosion composition, comprising: a carrier in the form of a liquid, gel, or solid, that is readily applied to a metal or metal alloy; an electrolytic modifier comprising a reducing agent, wherein the reducing agent comprises one or more of nitrite, sulfite, phosphite, or polyphosphate; and a plurality of spherical, ground state nonionic metal nanoparticles suspended in the carrier at a concentration of between about 0.5 ppm and about 100 ppm, wherein the spherical, ground state nonionic metal nanoparticles comprise a metal selected from the group consisting of gold, silver, platinum, and palladium, optionally alloyed with a metal selected from the group consisting of antimony, bismuth, and lead, or selected from the group consisting of stainless steel, austenite nickel-chromium alloys, and nickel-copper alloys, wherein the spherical, ground state nonionic metal nanoparticles have a diameter between about 1 nm and about 40 nm, wherein the spherical, ground state nonionic metal nanoparticles have a mean diameter and wherein at least 99% of the metal nanoparticles have a diameter within ± 3 nm of the mean diameter, and wherein the spherical, ground state nonionic metal nanoparticles have a size and shape so as to locate at grain boundaries of a metal or metal alloy upon application of the carrier to the metal or metal alloy. a carrier in the form of a liquid, gel, or solid, that is readily applied to a metal or metal alloy; an electrolytic modifier comprising a reducing agent, wherein the reducing agent comprises one or more of nitrite, sulfite, phosphite, or polyphosphate; and a plurality of spherical, ground state nonionic metal nanoparticles suspended in the carrier at a concentration of between about 0.5 ppm and about 100 ppm, wherein the spherical, ground state nonionic metal nanoparticles comprise a metal selected from the group consisting of gold, silver, platinum, and palladium, optionally alloyed with a metal selected from the group consisting of antimony, bismuth, and lead, or selected from the group consisting of stainless steel, austenite nickel-chromium alloys, and nickel-copper alloys, wherein the spherical, ground state nonionic metal nanoparticles have a diameter between about 1 nm and about 40 nm, wherein the spherical, ground state nonionic metal nanoparticles have a mean diameter and wherein at least 99% of the metal nanoparticles have a diameter within ± 3 nm of the mean diameter, and wherein the spherical, ground state nonionic metal nanoparticles have a size and shape so as to locate at grain boundaries of a metal or metal alloy upon application of the carrier to the metal or metal alloy. wherein the spherical, ground state nonionic metal nanoparticles comprise a metal selected from the group consisting of gold, silver, platinum, and palladium, optionally alloyed with a metal selected from the group consisting of antimony, bismuth, and lead, or selected from the group consisting of stainless steel, austenite nickel-chromium alloys, and nickel-copper alloys, wherein the spherical, ground state nonionic metal nanoparticles have a diameter between about 1 nm and about 40 nm, wherein the spherical, ground state nonionic metal nanoparticles have a mean diameter and wherein at least 99% of the metal nanoparticles have a diameter within ± 3 nm of the mean diameter, and wherein the spherical, ground state nonionic metal nanoparticles have a size and shape so as to locate at grain boundaries of a metal or metal alloy upon application of the carrier to the metal or metal alloy.