This is steel containing nickel as the predominant alloying element. The first nickel-steel armor plate, with 3.5% nickel, was known as Harveyized steel.
Nickel added to carbon steel increases the strength, elastic limit hardness, and toughness. It narrows the hardening range but lowers the critical range of steel, reducing danger of war page and cracking, and balances the intensive deep-hardening effect of chromium. The nickel steels are also of finer structure than ordinary steels, and the nickel retards grain growth. When the percentage of nickel is high, the steel is very resistant to corrosion. At high nickel contents, the metals are referred to as iron-nickel alloys or nickel-iron alloys. The steel is nonmagnetic above 29% nickel, and the maximum permeability is at about 78% nickel. The lowest thermal expansion is at 36% nickel. The percentage of nickel in nickel steels usually varies from 1.5 to 5%, with up to 0.80% manganese. The bulk of nickel steels contains 2 and 3.5% nickel. They are used for armor plate, structural shapes, rails, heavy-duty machine parts, gears, automobile parts, and ordnance.
The standard ASTM structural nickel steel used for building construction contains 3.25% nickel, 0.45% carbon, and 0.70% manganese. This steel has tensile strength from 586 to 689 MPa and a minimum elongation 18%. An automobile steel contains 0.10 to 0.20% carbon, 3.25 to 3.75% nickel, 0.30 to 0.60% manganese, and 0.15 to 0.30% silicon. When heat-treated, it has a tensile strength up to 551 MPa and an elongation 25 to 35%. Forgings for locomotive crankpins, containing 2.5% nickel, 0.27% carbon, and 0.88% manganese, have a tensile strength 572 MPa, elongation 30%, and reduction of area 62%. A nickel-vanadium steel, used for high-strength cast parts, contains 1.5% nickel, 1% manganese, 0.28% carbon, and 0.10% vanadium. The tensile strength is 620 MPa and elongation 25%. Univan steel for high-strength locomotive castings is a nickel-vanadium steel of this type. Unionaloy steel is an abrasion-resistant steel.
The federal specifications for 3.5% nickel carbon steel call for 3.25 to 3.75% nickel, and 0.25 to 0.30% carbon. This steel has a tensile strength of 586 MPa and elongation 18%. When oil-quenched, a hot-rolled 3.5% nickel medium-carbon steel, SAE steel 2330, develops a tensile strength up to 1516 MPa, and Brinell hardness of 223 to 424, depending on the drawing temperature. Standard 3.5 and 5% nickel steels are regular products of the steel mills, although they are often sold under trade names. Steels with more than 3.5% nickel are too expensive for ordinary structural use. Steels with more than 5% nickel are difficult to forge, but the very high nickel steels are used when corrosion-resistant properties are required. Nicloy, used fork tubing to resist the corrosive action of paper-mill liquors and oil-well brines, contains 9% nickel, 0.10% chromium, 0.05% molybdenum, 0.35% copper, 0.45% manganese, 0.20% silicon, and 0.09% max carbon. The heat-treated steel has a tensile strength of 758 MPa, with elongation 35%. The cryogenic steels, or low-temperature steels, for such uses as liquid-oxygen vessels, are usually high-nickel steels. ASTM steel A-353, for liquid-oxygen tanks at temperatures to -196°C, contains 9% nickel, 0.85% manganese, 0.25% silicon, and 0.13% carbon. It has a tensile strength of 654 MPa with elongation of 20%. A 9% nickel steel, for temperatures down to -196°C, contains 9% nickel, 0.80% manganese, 0.30% silicon, and not over 0.13% carbon. It has a minimum tensile strength of 620 MPa and elongation of 22%.
