17-4 Precipitation-Hardening Stainless Steel

Our 17-4 PH Stainless Steel (SS) is a precipitation-hardening martensitic stainless steel, with a chemical makeup of approximately 17% chromium and 4% nickel. Typical usage is seen in applications requiring high strength and an excellent level of corrosion resistance. The strength and toughness desired can be manipulated by the temperate range in the heat treatment process. Best Stainless offers high-quality standards of 17-4 stainless steel bar including UNS S17400, AMS 5643, ASTM A564, and ASTM A693 Grade 630. 
   17-4 PH is a chromium-nickel grade of stainless that may be hardened by a single low temperature precipitation-hardening heat treatment. Excellent mechanical properties at a high strength level may be obtained by such treatment. Scaling and distortion is minimized. 17-4 PH should not be used in the solution treated condition.  17-4 machines well, has excellent welding characteristics, and forges easily. The combination of good mechanical and processing properties makes this grade adaptable to a wide range of uses. Alloy 17-4 PH withstands corrosive attacks better than any of the standard hardenable stainless steels.

Properties
The physical properties of 17-4 PH stainless steel vary depending on any tempering processes done to the material. If you require specific physical properties for your application, please contact us to make sure this material will meet your needs.

Typical Uses
Typical applications for 17-4 stainless steel include:
Motor Shafts
Aircraft Structural Parts
Valve Stems
Gears

Introduction

Grade 420 stainless steel is a high-carbon steel with a minimum chromium content of 12%. Like any other stainless steel, grade 420 can also be hardened through heat treatment. It offers good ductility in its annealed state and excellent corrosion resistance properties when the metal is polished, surface grounded or hardened. This grade has the highest hardness - 50HRC - among all the stainless steel grades with 12% chromium.

Stainless steel grades that are similar to grade 420 stainless steels include martensitic steels such as the other versions of grade 420, having vanadium, sulphur and molybdenum in their composition, and the grade 440 series. Non-standard grade 420C has carbon content that is little higher than that of grade 420.

Martensitic stainless steels are ones with high hardness and high carbon content. These steels are generally fabricated using methods that require hardening and tempering treatments. The operating conditions of martensitic steels are affected by loss of material’s strength at high temperatures, and decrease in ductility at negative temperatures.

Key Properties

The following properties are mentioned for bar products in ASTM A276. The specification may not necessarily be similar for other forms, such as forgings and plate.

Chemical Composition

The compositional ranges of grade 420 stainless steels are given in following table: