Detailed description of 17-4 PH stainless steel and its different H conditions

17-4 PH Stainless Steel Overview

17-4 PH stainless steel is a precipitation hardening stainless steel known for its high strength, hardness and corrosion resistance.” The designation “H” followed by a number (e.g., H900, H1025, H1100, etc.) refers to different heat treatment conditions, each of which produces specific mechanical properties.

17-4 Types of H Conditions for PH Stainless Steel

1.H900: Precipitation hardening at approximately 900°F (482°C). This condition typically produces very high strength and hardness in the range of approximately 35-43 HRC. suitable for applications requiring maximum strength and hardness.

2.H1025: Precipitation hardens at approximately 1025°F (552°C). This condition provides a balance of strength and toughness with a hardness typically in the range of 30-36 HRC. Typically used in applications requiring a combination of strength and toughness.

3.H1075: Precipitation hardens at approximately 1075°F (580°C). This condition provides a higher level of strength compared to H1025, with hardnesses typically in the 33-39 HRC range. Used for applications requiring higher strength without sacrificing too much toughness.

4.H1100: Precipitation hardened at approximately 1100°F (593°C). This condition provides good strength and toughness with hardnesses typically in the 28-36 HRC range. Suitable for applications requiring a balance of mechanical properties and good machinability.

5.H1150: Precipitation hardens at approximately 1150°F (621°C). This condition provides good toughness and corrosion resistance with hardnesses typically in the 27-35 HRC range. Used for applications requiring moderate strength combined with good toughness and corrosion resistance.

6.Double H1150 Process: After the initial aging cycle (H1150), the material is subjected to a second aging process at the same temperature (approximately 1150°F or 621°C). This secondary aging process further refines the microstructure of the alloy and may slightly increase strength and hardness while optimizing other mechanical properties.” The “Double H1150” treatment is used to achieve specific mechanical properties to meet the requirements of high-stress applications where a balance of strength, toughness and corrosion resistance is critical. The exact properties achieved by Double H1150 can vary depending on the specific composition of the alloy and the parameters of the heat treatment process applied. In summary, double H1150 involves a two-step aging process at approximately 1150°F and is designed to maximize the performance of 17-4 PH stainless steel in demanding industrial and aerospace applications.

7.H1150M: Similar to H1150, but with a lower carbon content, which enhances toughness and reduces the risk of sensitization during welding.

Areas of application

17-4 PH stainless steel, due to its different H conditions, can provide engineers and manufacturers with the appropriate heat treatment options to meet the specific requirements of their applications, balancing factors such as strength, hardness, toughness, corrosion resistance, and processability. Each condition is optimized for specific mechanical properties while maintaining the overall characteristics of 17-4 PH stainless steel, making it a versatile choice for industries such as aerospace, medical, chemical processing, food processing, and oil and gas.

AISI630-1.4542-X5CrNiCuNb16.4