17-4PH - 1.4548 - AMS 5622 - AMS 5643 - AISI 630 - UNS S17400
Description
Alloy 1.4548 or 17-4PH is a martensitic, structure-hardening stainless steel that combines a hardness of approximately 43 HRC with very good corrosion resistance. This grade has a hardening peak at 480°C, which makes it easy to age after machining in an initially solution-treated state (condition A). The grade is also available in a pre-treated H1025 state (1.4548.4).
This aerospace-grade alloy is produced by VAR (Type 1) or ESR (Type 2) remelting in order to limit sulfur and phosphorus content and optimize inclusion cleanliness and microstructure. Ultrasonic testing is performed as standard on round products in accordance with AMS STD 2154 Class AA.
Stainless has 1.4548.4 Type 2 in stock, as well as various formats and product conditions to best meet your application needs. This product can also be cut into pieces by our service centers. cke zugeschnitten werden.
Main applications
Due to its good corrosion resistance, high hardness when treated (43HRC), and resilience, this grade is used in particular in the manufacture of aerospace components and in applications in the defense and energy sectors.
Metallurgy
The manufacturing process involves VAR (Type 1) or ESR (Type 2) remelting, which improves the cleanliness and homogeneity of the product. The hot working process produces a controlled microstructure and macrostructure. In the treated state, the microstructure consists of martensite and nanometric intermetallic precipitates that grow during aging. The AMS 5643 and AMS 5622 standards also guarantee less than 5% ferrite.
Machinability
Forgeability
The grade can be hot forged in the temperature range 950/1200°C. Solution treatment will be necessary to achieve maximum hardness.
Weldability
The alloy can be welded using most processes. Welding should preferably be carried out before aging to avoid embrittlement of the heat-affected zone.
Typical heat treatments
| For a target hardness ≥ 40HRC |
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A volume contraction of up to approximately 0.07% is to be expected during aging.
Corrosion resistance
This grade is highly resistant to corrosion and ranks among the best martensitic stainless steels. The microstructure contains little or no chromium carbides, making it highly resistant to intergranular corrosion.
Standard Sizes
- Round bars, pre-treated condition H1025 – Surface peeled or ground depending on diameter
- Other formats: please contact us