Métaux – acier inoxydable

Traduction française en cours de rédaction.

metaux-stenless-steel

ACIER INOXYDABLE 17-4PH

17-4PH is a martensitic precipitation-hardening stainless steel that provides an outstanding combination of high strength and the corrosion resistance of stainless steels. The strength, corrosion resistance and easy fabrication make 17-4PH a cost effective replacement for high strength carbon steels as well as other stainless steels.

Chemical Composition (wt. %)

UNS NO. NI CR C MN SI MO CU CB+TA S P FE
min. S17400 3.0 15.0 3.0 5xC Bal.
max. 5.0 17.5 0.07 1.0 1.0 0.05 5.0 0.45 0.03 0.04

Main Features

  1. Corrosion resistant.
  2. High tensile strength and hardness up to 600°F
  3. Good machinability and excellent welding characteristics.
  4. The combination of excellent mechanical and processing properties.

Main Applications

  1. Used where high strength and good corrosion resistance are required.
  2. Applications requiring high fatigue strength, good resistance to galling, seizing, and stress corrosion.
  3. Suitable for intricate parts requiring machining and welding.
  4. 17-4PH are widely used in the aerospace, chemical, petrochemical, food processing, paper and general metalworking.

Fabrication

17-4PH can be easily welded and processed by standard shop fabrication practices.

Hot forming

Hot working of 17-4PH should be performed at 950 -1200°C (1742 — 2192°F). After hot working, full heat treatment is required. This involves annealing and cooling to room temperature or lower. Then the component needs to be precipitation hardened to achieve the required mechanical properties.

Cold forming

Cold forming such as rolling, bending and hydroforming can be performed on 17-4PH, but only in the fully annealed condition. After cold working, stress corrosion resistance is improved by re-ageing at the precipitation hardening temperature.

Welding

Precipitation hardening 17-4PH can be readily welded using procedures similar to those used for the 300 series of stainless steels. Welding up to 100mm thick can be carried out without the requirement of pre heating due to its low hardness.