Stainless Steel 17-4PH Powder in 2024

Översikt

Stainless steel 17-4PH powder is a precipitation hardening martensitic stainless steel that can be used for metal 3D printing. It has high strength and hardness coupled with good corrosion resistance. 17-4PH contains approximately 4% copper which enables age hardening of the alloy through precipitation of copper-rich particles.

This article provides an overview of 17-4PH powder including its composition, properties, processing, applications, suppliers, and comparisons to other alloys. Key details are summarized in the tables below.

17-4PH Powder Composition

17-4PH gets its name from its composition which includes approximately 4% copper. The main alloying elements are:

Element	Vikt %
Krom	15 – 17.5%
Nickel	3 – 5%
Koppar	3 – 5%
Mangan	≤ 1%
Kisel	≤ 1%
Kol	≤ 0.07%
Sulfur & Phosphorus	≤ 0.04%
Kväve	≤ 0,03%

The copper content results in precipitation hardening which increases the strength and hardness of 17-4PH substantially. The chromium provides corrosion resistance. Nickel also boosts corrosion resistance while enhancing ductility and toughness.

17-4PH Powder Properties

17-4PH powder offers an excellent combination of high strength and good corrosion resistance. Key properties include:

Fastighet	Beskrivning
Styrka	Tensile strength up to 1,380 MPa, yield strength up to 1,240 MPa
Hårdhet	Up to 44 HRC after aging
Motståndskraft mot korrosion	Better than 400 series stainless steels due to copper
Bearbetbarhet	More difficult to machine than 300 series due to higher strength
Magnetism	Slightly magnetic due to martensitic microstructure
Svetsbarhet	Lower weldability than 300 series due to precipitation hardening

The strength, hardness, and corrosion resistance can be tailored through heat treatment. Solution annealing renders the alloy soft and ductile. Subsequent aging induces precipitation of copper-rich particles which impedes dislocation movement, thereby hardening and strengthening the material.

17-4PH Processing

17-4PH powder can be processed via several metal 3D printing methods:

Fusion av laserpulverbäddar (L-PBF)
Fusion av pulverbäddar med elektronstråle (E-PBF)
Deposition med riktad energi (DED)

L-PBF is one of the most common approaches. Process parameters must be carefully controlled to achieve dense, crack-free parts and avoid residual stresses.

Typical processing conditions for 17-4PH powder in L-PBF:

Skikttjocklek: 20-50 μm
Laser power: 100-400 W
Scan speed: 100-1500 mm/s
Avstånd mellan luckorna: 80-120 μm
Beam diameter: 50-100 μm

A stress relief heat treatment is recommended after printing to relieve residual stresses. The printed parts can be solution annealed and aged to increase hardness and strength.

17-4PH Applications

17-4PH is used for metal 3D printed parts requiring high strength, hardness, and moderate corrosion resistance across a variety of industries:

Aerospace: Turbine blades, impellers, fasteners, brackets
Automotive: Transmission components, turbocharger parts
Oil & gas: Valves, wellhead parts, pumps
General engineering: Tooling, fixtures, molds

The high hardness after aging makes 17-4PH suitable for wear-resistant applications. It can substitute for hard-to-machine materials like tool steels for injection molds and dies. The alloy is commonly used for high-strength structural brackets and housings.

17-4PH Powder Suppliers

17-4PH powder is commercially available from leading metal powder manufacturers:

Leverantör	Produktkvaliteter	Storleksintervall
Sandvik	Osprey 17-4PH	15-45 μm
Snickare	17-4PH	15-45 μm
Praxair	17-4 PH	15-53 μm
LPW-teknik	17-4PH	15-45 μm
Erasteel	17-4 PH	20-150 μm

Prices range from $50/lb to $90/lb depending on quantity ordered. Custom particle size distributions and high purity grades (e.g. phosphate passivated) are available.

17-4PH vs Other Alloys

17-4PH compares to stainless steel and tool steel alloys as follows:

Legering	Styrka	Motståndskraft mot korrosion	Kommentarer
17-4PH	Mycket hög	Måttlig	Precipitation hardening; high hardness; good strength and corrosion resistance combination
316L	Medium	Utmärkt	Standard corrosion resistant stainless; low strength; not heat treatable; cheaper
PH 13-8	Hög	Utmärkt	Precipitation hardening; high strength and corrosion resistance; contains 8% nickel
H13 Verktygsstål	Mycket hög	Måttlig	Standard tool steel; high hardness but lower corrosion resistance; more expensive

VANLIGA FRÅGOR

What are the main advantages of 17-4PH stainless steel?

The main advantages of 17-4PH are its high strength and hardness coupled with moderate corrosion resistance. Hardness values up to 44 HRC are possible through aging. It offers substantially higher strength than 300 series stainless steels.

What is 17-4PH stainless steel used for?

Common applications of 17-4PH include structural components like brackets and housings, wear-resistant parts, plastic injection molds and dies, impellers, valves, and aerospace components. It is widely used across aerospace, oil & gas, automotive, and general engineering.

Why is 17-4PH suitable for metal 3D printing?

17-4PH has low thermal conductivity and coefficient of thermal expansion, making it less prone to residual stress and cracking during printing. Its high hardness enables printing of wear resistant tooling. The alloy is commonly available in powder form.

What heat treatment is used for 17-4PH?

17-4PH is typically solution annealed at 1038-1066°C then aged at 371-427°C to precipitate copper-rich particles. This causes the alloy to harden and strengthen substantially. Stress relieving prior to heat treatment is recommended.

How does 17-4PH compare to 316L and H13 tool steel?

17-4PH has much higher strength and hardness than 316L stainless steel but lower corrosion resistance. Compared to H13 tool steel, 17-4PH offers better corrosion resistance with slightly lower hardness. 17-4PH provides a good balance between hardness, strength, and corrosion resistance.

What precautions are needed when 3D printing 17-4PH?

Careful process parameter selection and stress relieving between layers is important to minimize residual stresses and cracking. Print orientation, support structures, and resolution/layer height must also be optimized for complex geometries.

What suppliers offer 17-4PH powder?

Leading suppliers of 17-4PH powder include Sandvik, Carpenter Additive, Praxair, LPW Technology, and Erasteel. Powder is available in different size distributions customized for AM processes like DED and L-PBF.