- High strength metal with good toughness at high temperatures
- Monel K500 chemistry and specifications
Also known as alloy K500, Monel K500 screws combine the outstanding corrosion resistance of Monel 400 with increased strength and hardness. These additional attributes of Monel K500 screws are a result of an age hardening process where aluminum and titanium are added to the nickel-copper base and then precipitated throughout the matrix. This process gives K500 approximately 3 times the yield strength ( 110ksi vs 45ksi) and double the tensile strength (160ksi vs 83ksi) when compared 400. Monel K500 screws will retain their strength to 1200°F and even retain their ductility as low as -400°F.
Corrosion Resistance of K500
Monel K500 screws offer a unique combination of high strength with similar corrosion resistance to Monel 400 and improved resistance to a sour-gas environments. Stronger than 400, alloy K500 even retains this strength in corrosive conditions, resisting both pure and salt water, as well as non-oxidizing mineral acids, salts, alkalis, and sour gas. The exception being that Monel K500 screws can be more prone to stress-corrosion cracking in some environments than Monel 400. In addition, stagnant or slow-moving sea water can cause fouling which is followed by pitting, but pitting typically slows after initial attack.
Outstanding Low Temperature Capabilities
Monel K500 screws are virtually non-magnetic and spark resistant, even at temperatures down to -200°F. Though in some applications, Monel K500 can develop a magnetic layer during processing when aluminum and copper are selectively oxidized during heating, leaving a magnetic nickel-rich film on the outside. This can be corrected by pickling or bright dipping in acid, which will remove any magnetic film and restore it to a non-magnetic condition. In addition, Monel K500 screws also offer outstanding low temperature properties. When utilized at subzero temperatures, these screws actually increase their tensile and yield strengths, while ductility and toughness are virtually unchanged. Hence, Monel K500 screws are utilized in many cryogenic applications.
Monel K500 (alloy K500), UNS N05500 (QQ-N-286), is a precipitation-hardenable nickel-copper alloy that combines the corrosion resistance of Monel alloy 400 with greater strength (over 2x as strong) and hardness. It also has low permeability and is nonmagnetic to temperatures as low as -150°F (-101°C).
Monel K500 Specifications: BS3075NA18 (Wire), BS3076NA18 (Rod and Bar), ASTM B 865 (Rod and Bar), DIN 17752 (Rod and Bar), DIN 17753 (Wire), DIN 17754 (Forgings), QQ-N-286 (Rod, Bar, Wire, and Forgings), SAE AMS 4676 (Rod and Bar), ASME Code Case 1192 (Rod and Bar), ISO 9723 (Bar), ISO 9724 (Wire), ISO 9725 (Forgings), Werkstoff 2.4375