Maraging Steel

Quality Processing for Maraging Steels

Maraging steels stand apart for their unique ability to combine ultra-high strength with excellent toughness and ductility — properties that are critical in the most advanced aerospace and defense applications. At Paulo, we’ve refined our processes to bring out the full performance potential of maraging alloys through tight control over every thermal step. Leveraging our proprietary datagineering approach, we deliver precise, repeatable outcomes tailored to your performance specs.

Strength Through Aging

Unlike carbon steels that rely on carbon content for strength, maraging steels achieve superior mechanical properties through a two-step thermal process: solution annealing followed by precipitation hardening (aging). Aging promotes the precipitation of intermetallic compounds, significantly increasing hardness and tensile strength while maintaining core toughness. These characteristics make maraging steels a go-to choice for mission-critical aerospace components like helicopter rotor shafts, missile skins, and high-performance tooling.

Machinability Advantage of Maraging Steels

One of the key practical benefits of maraging steels is their availability in the solution annealed condition. This initial soft state makes them extremely machinable, allowing manufacturers to produce complex, high-precision parts with minimal tool wear and effort. After machining, parts are easily brought to final strength through a controlled precipitation hardening (aging) process without the need for an additional solution annealing step — resulting in shorter lead times and minimized distortion.

Maraging Steel Components We Process

Aerospace structural components
Missile housings

Helicopter rotor masts
Tooling and dies

High-performance fasteners

Maraging Steel Alloys We Process

Vascomax 200, 250, 300

These common maraging steel grades (also known as 18Ni(200/250/300)) are named for their approximate tensile strength in ksi. Each grade offers a balance of high strength and ductility with excellent dimensional stability during aging.

Vascomax 250

One of the most commonly used maraging steels, Vascomax 250 (18% Ni) offers excellent machinability in the annealed state and reaches final properties through aging at approximately 900°F.

• Typical Hardness Range (after aging): 50–55 HRC
• Aging Temperature: 900–950°F
• Common Uses: Structural aerospace components, drive shafts, missile systems

Vascomax 300

Provides the highest strength of the maraging steel family while retaining good notch toughness.

• Typical Hardness Range: 53–58 HRC
• Aging Temperature: 900–950°F
• Common Uses: Missile skins, tools, mandrels, high-strength shafts

Additive Manufacturing Applications

In addition to traditional bar and plate stock, maraging 250 and 300 steels are widely utilized in additive manufacturing (AM), particularly in processes like Laser Powder Bed Fusion (LPBF). These steels print reliably and maintain desirable mechanical properties after post-processing.

For AM parts made from maraging steels:
• Solution Annealing + Aging is required to restore full mechanical properties after printing.
• Hot Isostatic Pressing (HIP) is sometimes recommended, especially for critical applications, to eliminate internal porosity and enhance performance.

Heat Treatment Processes for Maraging Steels

Vacuum Heat Treating

Minimizes oxidation and distortion, critical for aerospace-grade components.

Annealing

Achieves a soft, ductile microstructure for ease of machining and forming. Performed in vacuum furnaces to eliminate oxidation.

Precipitation Hardening (Aging)

Enhances strength by forming intermetallic precipitates. Controlled temperature and time cycles in vacuum furnaces ensure optimal properties.