UNS N05500 DIN 2.4375 Alloy 500 Monel Round Bars

Product Description

Monel Alloy K-500—designated as UNS N05500 under American standards, DIN W.Nr. 2.4375 in Germany, BS NA18 in the United Kingdom, and ISO NW5500—is a age-hardenable nickel-copper alloy that combines the excellent corrosion resistance of Monel 400 with significantly higher strength and hardness. Governed by primary supply specifications including ASTM B865, ASME SB865, AMS 4676, and NACE MR0175 for sour gas environments, its chemical composition requires a minimum of 63.0 percent nickel, 27.0 to 33.0 percent copper, 2.30 to 3.15 percent aluminum, and 0.35 to 0.85 percent titanium, with maximum limits of 2.0 percent iron, 1.5 percent manganese, 0.50 percent silicon, 0.25 percent carbon, and 0.01 percent sulfur.

Physically, Alloy K-500 features a density of 8.44 grams per cubic centimeter (0.305 pounds per cubic inch), a melting range of 1315 to 1350 degrees Celsius (2400 to 2460 degrees Fahrenheit), an elastic modulus of 179 gigapascals, and a thermal conductivity of 17.5 watts per meter-kelvin. Unlike Monel 400, Alloy K-500 remains non-magnetic down to extremely low cryogenic temperatures below minus 100 degrees Celsius, making it suitable for non-magnetic shafting and drilling tools.

Mechanically, the properties depend on the heat-treated condition. In the solution annealed state, round bars display a tensile strength of 620 to 760 megapascals (90 to 110 ksi), a 0.2 percent yield strength of 275 to 415 megapascals (40 to 60 ksi), an elongation of 25 to 50 percent, and a hardness of 140 to 180 Brinell. When age-hardened after solution annealing, the formation of gamma prime precipitates elevates the minimum tensile strength to 965 to 1100 megapascals (140 to 160 ksi), the yield strength to 690 to 790 megapascals (100 to 115 ksi), elongation to 20 to 30 percent, and hardness to 28 to 35 Rockwell C (280 to 330 Brinell). Cold-drawn and aged bars achieve even higher mechanical limits, with tensile strength up to 1310 megapascals (190 ksi), yield strength up to 965 megapascals (140 ksi), and hardness up to 38 Rockwell C.