15-5 PH Stainless Steel
SS 15-5, commonly known as 15-5 PH or PH 15-5 stainless steel, is a martensitic, precipitation-hardening steel with exceptional strength due to its lower corrosion-resistant properties that excel at high temperatures. This stainless steel is a predominant composition of nickel, chromium, and copper, which makes it tougher than its 17-4 variant. It is also notable for its excellent creep and fatigue resistance, which suits it to a ton of industries, including nuclear, medical, petrochemical, offshore, marine, and aerospace.
The steel’s steep demand is reflective of its ability to withstand high stress and stringent atmospheric conditions, including humidity, temperature, and air pressure. In addition, it exhibits good mechanical properties that can be further enhanced by the heat treatment method. On par with this feature is its toughness which stands up to its application in transverse and longitudinal directions in both welds and base metal.
Other elements present in steel PH 15-5 are phosphorus, sulfur, silicon, and manganese, to list a few, which all combine to make it valuable in manufacturing valves, nozzles, shafts, gears, and fasteners. What gives this metal its precipitation qualities is the combination of martensitic and ferritic microstructures. This creates a good balance of strength, toughness, and machinability for the right reason.
While martensitic steels are strong and durable, they are brittle and difficult to work with. Ferritic stainless steels, on the other hand, are more ductile and machinable but hardly withstand heavy loads.
Looking for a SS 15-5 distributor? Call the top Stainless Steel Supplier in California at 714-632-0140 or Toll-Free at 800-854-6777.
SS 15-5 Mechanical Properties
- Brinell hardness: 420
- Elastic (Young’s, Tensile) Modulus: 196 GPa (28427 ksi)
- Impact strength (V-notched Charpy): 10J (7.38 ft-lb)
- Elongation at break: 8%
- Rockwell C hardness: 44.2
- Rockwell B hardness: 104
- Poisson’s ratio: 0.27 – 0.30
- Tensile strength (Yield proof): 1275 Mpa (1489 x 102 psi)
- Tensile strength (Ultimate UTS): 1380 MPa (200 x 103 psi)
- Knoop hardness: 451
- Vickers hardness: 445
SS 15-5 Chemical Properties
Element | min | max |
Carbon | 0 | 0.07 |
Manganese | 0 | 1.00 |
Silicon | 0 | 1.00 |
Phosphorus | 0 | 0.040 |
Sulfur | 0 | 0.030 |
Chromium | 14.40 | 15.50 |
Nickel | 3.50 | 5.50 |
Copper | 2.50 | 4.50 |
Columbium plus Tantalum | 0.15 | 0.45 |
The above composition makes steel PH 15-5 highly corrosion resistant.
SS 15-5 Thermal Properties
- Melting point: 1405 °C (2561 °F)
- Thermal expansion coefficient: 10.8 µm/(m⋅°C)
- Thermal conductivity: 17.8 W/(m⋅°C)
- Specific heat capacity: 0.420 J/g°C
SS 15-5 Electric properties
- Surface resistance: 77.0 µΩ ANSI
- Electrical conductivity: 2.2% IACS
SS 15-5 Other Properties
- Density:486 lb/ft3(7.8 g/cm3)
SS 15-5 Fabrication & Working Instructions
SS 15-5 is primarily available in the annealed state. When heat treated at lower temperatures, its mechanical properties and durability increase drastically. It is suitable for various fabrication techniques, such as machinability, welding, cold working, forming, and annealing. Its high machinability makes it easy to cut, shape, and form into diverse components and products under varying conditions.
Welding utilizing appropriate techniques such as electric resistance welding and fusion welding works well for this steel-grade material. A recommended filler metal for this process is AWS E/ER630. Although not all experts recommend cold working. However, when done moderately, the formed alloy turns out even, tough, and appealing. Speaking of forming, this technique requires working with the steel in its overaged condition.
The annealing process for PH 15-5 requires heating it at 1900°F (1038°C) for 1 hour, then cooling it rapidly to reduce its internal stresses and make it easier to work with.
SS 15-5 Heat Treatment
Stainless Steel Grade 15-5 PH relies on heat treatment to enhance its mechanical properties and this can be done in various conditions such as annealing, ageing or precipitation hardening, and two-step ageing.
In the annealing condition (condition A) the steel is heated to 1900°F (1038°C) above its recrystallization temperature for half an hour and then left to air cool. This helps to remove stresses and homogenize the microstructure, making it highly ductile. The next condition, known as ageing or H 900 entails soaking the steel at 900°F (482°C) for an hour and letting it air cool to increase its hardness and tensile strength.
SS 15-5 may also be precipitation hardened at various ageing temperatures to reach the desired levels of strength and hardness. Other names for this condition include H1025, H925, H1150, H1075, and H1100. The steel is soaked for 4 hours at the desired temperature and left to air cool.
Two-step ageing, also known as double ageing or condition H 1150M, requires ageing the material at two different temperatures to optimize its mechanical properties, including toughness and resistance to stress corrosion cracking (SCC). First, it is soaked at 1400°F (760°C) for two hours and cooled in the air. Thereafter, it’s heated for four hours at 1150°F (621°C) and air-cooled.
Benefits of Steel SS 15-5
Stainless steel SS 15-5 has a ton of applications, owing to its excellent strength-to-weight ratio, fatigue resistance, and corrosion resistance, among others. It is used to manufacture medical, marine, aerospace, cooling, and automotive parts. These include scalpels, window frames, valves, gears, turbine blades, HVAC components, roofing systems, fasteners, pumps, and fittings.
Given the steel’s non-toxicity when heated or cooled rapidly, it is safe to use to produce cutlery and cookware, such as spoons, forks, knives, kettles, pots and pans, and steam cookers. Similarly, its application in the medical industry results from its corrosion resistance, low weight, and superb strength.
Another notable attribute of this alloy is its low maintenance requirements. It is easy to clean and polish using mild soaps, detergents, solvent degreasers, and water or soft cloth. In contrast, harsh or abrasive cleaning agents tend to damage its surface finish and render it highly susceptible to corrosion and rust. Although it can withstand high temperatures, direct exposure to intense heat or flames for long periods that result in discoloration or warping.
Friend Metals: Your SS 15-5 Supplier
Are you looking for a reliable supplier to fulfill your metal fabrication or steel processing needs? If so, you need not look beyond Friend Metals Distributor. At our company, we stock a wide variety of products, including PH 15-5. Our steel-grade SS 15-5 is manufactured in compliance with the highest quality standards, which guarantees their strength, durability, and reliability in various applications.
We also process custom orders and ship them to clients worldwide in a timely manner. Our professional team of sales representatives and metal service technicians are always willing to serve you. Contact us today for a quote or for more information.