Stainless Steel 15-5

Stainless Steel 15-5 in CNC Machining

Stainless Steel 15-5, also known as 15-5 PH, is a martensitic precipitation-hardening stainless steel alloy. It has high strength, good corrosion resistance, and excellent toughness.

When machining Stainless Steel 15-5, we have several considerations to ensure the best results. We use coated carbide tools or high-speed steel (HSS) and coolants. We maintain appropriate cutting speeds and optimize feed rates. We ensure effective chip evacuation and use climb milling techniques. Though it cannot be anodized, we do post-machine operations like surface finishing, hot working, age hardening, and annealing. We use heat treatments to enhance its properties.

Stainless steel 15-5 has a chemical composition of around 14.0-15.5% chromium, 3.5-5.5% nickel, and 2.5-4.5% copper. Additional elements include manganese (up to 1.0%), silicon (up to 1.0%), and trace amounts of phosphorus and sulfur. The alloy also contains columbium (niobium) and tantalum in the range of 0.15-0.45%. Carbon is limited to 0.07% or less, and the balance is iron.

What is Stainless Steel 15-5?

Stainless Steel 15-5 is a precipitation-hardening, martensitic stainless steel alloy. It is also known by other trade names, such as UNS S15500 or XM-12. The “15-5” designation indicates it contains approximately 15% chromium and 5% nickel. This alloy has excellent corrosion resistance, high strength, and good toughness.

One of the notable features of Stainless Steel 15-5 is its ability to be precipitation-hardened through heat treatment. This involves a two-step process: first, the alloy is solution-treated at a high temperature and then aged at a lower temperature to achieve the desired mechanical properties. This process enhances the strength of the material while maintaining its corrosion resistance.