UNS S17700 (17-7 PH, AZ 127) Stainless Steel
UNS S17700 is a precipitation hardenable alloy used for various applications such as aircraft and aerospace components and tools, nuclear reactors, medical implants, springs, and fasteners. Alloy 17-7 PH (UNS S17700) is known for its corrosion resistance and high strength properties, making it the ideal choice for demanding and critical applications in the aerospace, medical, and automotive industries.
Alloy 17-7 PH is an age-hardenable stainless steel that combines the strong mechanical properties of a martensitic matrix with the corrosion resistance of austenitic stainless steels. When heated to temperatures between 550-900°F, the alloy is capable of reaching superior strength levels, due to its precipitation-hardening mechanism known as aging.
The addition of Nb and Ti to the alloy structure refines and stabilizes the grain size, giving the material superior strength and durability, as well as improved machinability on aged material. Furthermore, the annealing temperature and hardness range of the material allow it to be welded and heat-treated easily.
While age hardening will raise the material cost of 17-7 PH over that of other stainless steels, its combination of corrosion resistance and superior mechanical properties makes it an ideal choice for demanding applications. The steel has proven to be a cost-effective alternative to other high-end materials, particularly in aerospace components, where the combination of high strength and ductility make it the perfect choice for structural components and components such as guides, rails, tubes, channels, and similar parts.
17-7 PH’s combination of properties makes it suited to a wide range of industries, particularly those that rely on high strength, corrosion resistance, and light weight. Its ability to withstand temperatures up to 680°F and its excellent corrosion resistance in marine coupled with its wear-resistance make it an excellent choice for medical and aerospace components, as well as architectural and construction applications. Furthermore, its wear resistance makes it well suited to aircraft fixtures, tooling components, and wire and marine electrical components.
17-7 PH stainless steel is easy to fabricate and can be machined to desired dimensions and shapes. It is important to note that when machining 17-7 PH, it is important to use tools designed for stainless steels, as the high hardness and wear resistance can result in shorter tool life with standard tools. Care should also be taken when machining 17-7 PH, as its age-hardenable nature can lead to a harder material than expected near the edges of the machined part.
17-7 PH stainless steel is a cost-effective, high strength, and corrosion resistant material that can be used in applications requiring high strength and corrosion resistance. Its benefits generally outweigh its costs, making it a cost-effective alternative to other materials in many applications. The combination of corrosion resistance, high strength, and light weight make it the ideal material for demanding applications in the aerospace, medical, automotive, and other industries.
