ThePipingMart Blog Grades P15 Alloy Steel (ASTM A335 P15) – Composition, Properties, and Uses

P15 Alloy Steel (ASTM A335 P15) – Composition, Properties, and Uses

P15 Alloy Steel Grade - Properties, Uses, Composition.

ASTM A335 P15  is an iron-based alloy with a high chromium and nickel content. It is one of the most commonly used alloys in producing mechanical components due to its excellent properties, such as corrosion resistance, heat resistance, and machinability. Let’s take a closer look at this versatile alloy and explore its composition, chemical properties, mechanical properties, physical properties, uses, corrosion resistance, heat resistance, heat treatment, and machining processes.

P15 Alloy Steel  Composition

ASTM A335 P15 contains iron (Fe) as its main alloying element. Other elements present in this alloy are chromium (Cr) and nickel (Ni). The percentages of these elements vary depending on the specific type of steel grade. For example, some grades contain up to 25% Cr and 20% Ni while others have lower levels of these elements.

Carbon Silicon Manganese Phosphorous Sulphur Molybdenum Nickel Chromium Copper Others
0.05-0.15 1.15-1.65 0.30-0.60 0.025 0.025 0.44-0.65

P15 Alloy Steel Chemical Properties

ASTM A335 P15 has excellent chemical properties, such as high corrosion resistance due to its chromium content. Its nickel content also makes it resistant to oxidation at elevated temperatures. It is also highly resistant to stress-corrosion cracking due to its higher tensile strength.

P15 Alloy Steel Mechanical Properties

One of the main advantages of using ASTM A335 P15 is its very good mechanical properties, such as high tensile strength and yield strength. Additionally, it has a relatively low thermal expansion coefficient, making it suitable for applications where the temperature fluctuates rapidly.

Condition Tensile Yield 0.2% offset Elongation (%in 2″) Reduction of Area Brinell Hardness Rockwell Hardness
Ann 363 Bhn C33
H900 190,000 psi 170,000 psi 6% 15% 388 Bhn C40
H1025 155,000 psi 145,000 psi 8% 27% 331 Bhn C35
H1075 145,000 psi 125,000 psi 9% 28% 311 Bhn C32
H1150 135,000 psi 105,000 psi 11% 30% 277 Bhn C28
H1150-M 115,000 psi 75,000 psi 14% 35% 255 Bhn C25

P15 Alloy Steel Physical Properties

This alloy has good physical properties, such as low thermal conductivity, which makes it suitable for applications requiring thermal insulation. Additionally, it has good ductility, allowing easy machining and forming. Furthermore, ASTM A335 P15 has excellent wear resistance due to its hardness which makes it ideal for wearing parts in machinery or tools subjected to high loads or abrasion during operation.

ASTM A335 P15 Equivalent

ASTM A335 Grade P15 ASME SA 335 Grade P15

P15 Alloy Steel Uses

This versatile alloy can be used in various applications ranging from automotive components such as piston rings and connecting rods to power generation equipment such as turbines and boiler tubes. It can also be used in oil & gas pipelines due to its high corrosion resistance property, which prevents rusting even under extreme conditions like salt water or acidic environments.

  • Grade P15 is an alloy steel that is often used in the automotive industry.
  • Grade P15 is a high-strength steel that can be heat-treated to achieve various desired properties.
  • Grade P15 is often used to produce engine and transmission components.
  • Grade P15 can also produce suspension and steering components.
  • Grade P15 is also often used in the production of body panels and other exterior components.
  • Grade P15 is also sometimes used in the production of interior components such as seats and door panels.
  • Grade P15 can also be used to produce electrical components.
  • Grade P15 is also sometimes used to produce fasteners and other hardware.
  • Grade P15 is also sometimes used in the production of welding consumables.
  • Grade P15 is also sometimes used in the production of other materials, such as tool steels

Corrosion Resistance

The combination of chromium and nickel in this alloy gives it superior corrosion resistance compared to other alloys without these elements present in them, making it an excellent choice for applications exposed to harsh chemicals or salt water environments like offshore platforms or marine vessels, etc. It is also highly resistant to pitting caused by corrosive acids like sulfuric acid or hydrochloric acid etc., making it suitable for use in various industrial processes involving corrosive chemicals/substances like petrochemical plants, etc.,

Heat Resistance

Due to its higher chrome content, this alloy exhibits excellent heat resistance allowing it to withstand temperatures up to 1500°C without any significant loss in mechanical properties making it suitable for use in applications that involve higher temperatures, like furnaces or combustion engines, etc.,

Heat Treatment

This alloy can be hardened by subjecting it through various heat treatment processes like quenching & tempering or normalizing & annealing, depending upon the desired hardness level needed for the application at hand


Due to its good machinability characteristics, this alloy can be easily machined using conventional tools & techniques. It requires no special considerations during cutting operations because of its high ductility characteristics. Also, this grade does not require extensive finishing after machining operations due to its smooth surface finish qualities.


In conclusion, Alloy Steel Grade P15 offers great versatility when used across different industries due to its unique combination of chemical , mechanical, physical & corrosion resistant properties. It can be used across multiple industries ranging from automotive components, power generation equipment, and oil & gas pipelines right throughout o industrial processes involving corrosive chemicals/substances. This grade provides exceptional value when selected over other alloys because of the many benefits of using this particular grade. You must select the right grade according to your specific application requirements to get maximum value out of your investment—intended Audience: Engineers and manufacturers who work with Alloy Steels.

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