Maraging C350

Maraging C350 – A maraging steel containing 12.0% cobalt and 4.8% molybdenum. Maraging C350 maraging steel is essentially iron based, with the main alloying additions being nickel, cobalt and molybdenum, in addition to significant additions of aluminium and titanium and maintaining a low carbon content, with very high mechanical properties and relatively low carbon content.

 

Other Names

  • Maraging 350
  • Vascomax C350
  • Vascomax C350 Nickel Maraging Alloy
  • ATI C-350

 

Standard :

  • AMS 6515
  • MIL-S-46850
  • UNS K93160

 

Feature

Produced by vacuum arc remelting, this steel has very high strength, with a nominal tensile strength of 350 ksi (2415 MPa) and above-average toughness. The alloy retains its strength up to 450°C and retains good notched impact down to -50°C and below. This material can be nitrided. High toughness while maintaining ease of weldability. Dual Vacuum Melting (VIM+VAR) for ultimate performance and high purity, easily meeting AMS 6515 / MIL-S-46850D / UNS K93160 and customer specifications.

 

High performance of Maraging 350 Steel:

 

Excellent mechanical properties

  • High yield strength and ultimate tensile strength
  • High toughness, ductility and impact strength
  • high fatigue strength
  • High compressive strength
  • Sufficient hardness and wear resistance for many tooling applications

 

Excellent workability

  • High crack growth resistance
  • Easy to form – cold, warm, hot (no process annealing)
  • Good weldability without preheating or postheating
  • Excellent polishability

 

Advantages in practical application

  • Low coefficient of expansion minimizes thermal inspection
  • Better pitting and corrosion resistance than common tool steels
  • Good repair weldability
  • Excellent mechanical properties extend tool life
  • Easy to rework and return to extend tool life

 

Physical Properties:

Property
Density, lb /in3 .292
Modulus of Elasticity 29.0 x 10-6 psi
Average Co of Thermal Expansion 6.3 x 10-6 in/in/°F

 

Delivery Conditions for Raw Materials

C350 Maraging steel raw material is usually supplied in the annealed and descaled condition before final heat treatment, in which the microstructure consists of fine martensite. The alloy is very tough, relatively soft (38Rc Max.), therefore, readily machined and formed.

 

Maraging 350 Machinability (Annealed):

 

Operation Tool Material Tool Geometry Depth of cut Width of cut Feed Cutting Speed Wearland Cutting Fluid
Turning M2 or T-15 BR: 0°; SR: 10°
SCEA: 15°; ECEA: 5°
Relief: 5°; NR: 0.030 in		 0.060 in — 0.009 in/rev 80 ft/min 0.060 in Soluble oil (1:20)
Turning C3 BR: -5°; SR: -5°
SCEA: 15°; ECEA: 15°
Relief: 5°; NR: 0.030 in		 — 0.009 in/rev 475 0.010 Soluble oil (1:20)
Face milling M2 or M-7 AR: 5°; RR: 5°; CA: 45°
ECEA: 10°; CI: 8°		 0.060 2 in 0.005 in/tooth 140 0.060 Highly chlorinated oil
Face milling C2 AR: 10°; RR: 0° CA: 45°
ECEA: 10° CI: 8°		 0.060 2 0.005 in/tooth 330 0.015 Dry
Peripheral end milling M2 Helix Angle: 30°; RR: 10°
CA: 45° x 0.060 in; CI: 7°		 0.250 0.750 0.004 in/tooth 225 0.012 Soluble oil (1:20)
End mill slotting M2 Helix angle: 30°; RR: 10°
CA: 45 x 0.060 in; CI: 7°		 0.250 0.750 0.002 in/tooth 140 0.012 Highly chlorinated oil
Drilling M1 118° plain point; CI: 7° 0.500 (through hole) — 0.005 in/rev 100 0.015 Highly sulfurized oil
Reaming M2 Helix angle: 0°; CA: 45°
CI: 7°		 0.500 (through hole) — 0.009 in/rev 60 0.006 Highly sulfurized oil
Tapping M1 2 flute plug; 75% thread 0.500 (through hole) — — 150 Undersize threads Highly sulfurized oil

 

Heat treatment after processing

Solid Solution Aging to final properties after machining the finished product is a relatively low temperature process to achieve high strength and toughness. This low temperature treatment allows machining close to final dimensions because distortion is minimal. Maraging steel retains its strength up to 450°C (840°F), can be nitrided, and has corrosion resistance similar to standard martensitic stainless steels.

 

Heat Treatment Aging Process: (Non Die Casting Applications)

Material is to be heat treated to 900 F +/- 10 holding at temperature for 6 hours then cooling at room air temperature. During the aging treatment maraging shrinks uniformly and predictably on all dimensions .001 in/in

 

Heat Treatment Aging Process: (Die Casting Applications)

Following the rough machining of the die, anneal at 1500-1525 F for 1 hour per inch of thickness is recommended. After finish machining, an aging heat treatment of 980-1000 F for 6 hours is recommended.

 

Minimum Properties after Aging:

Hardness ………….…….… 56 Rc

Charpy V-notch …..….… 6 ft/lbs. min

Reduction of Area ….…. 25%

Elongation …………….….. 2.8%

Yield Strength …………… 330 ksi

Fracture Toughness ….. 25

 

Quality Control

We have on-site inspectors who can test materials according to your requirements. All supplied materials are fully traceable and have inspection certification to BS EN 10402 3.1.

 

Availability

Maraging 350 is available for bar, bar, billet (up to 18″ diameter), plate, sheet, forging, seamless pipe, welded pipe, seamless pipe, welded pipe. Contact sales for all stock availability.

 

Machinability

Maraging steels are usually processed in the annealed condition, however, they can be processed in the maraging condition. Parts can be machined to near-finish size due to minimal deformation due to low temperature maraging. Maraging steel in the annealed condition is comparable to 4340. However, when maraging is aged, the type of cutting tool and speedschange. Rigid equipment, firm tool supports, sharp tools and abundant coolant are essential.

In addition, a small shrinkage of about 0.05% due to martensitic aging results in good dimensional stability.

 

Weldability

C350 steel has good weldability. It’s weldable without preheat, in both the annealed and aged condition. Only an aging heat treatment is needed to restore in the weldseam.

 

Technical Data Sheet

Chemical Composition Limits
Weight% Ni Co Mn Si C B P S Al Mo Ti Zr
Maraging 350 18.50 12.0 0.10 max 0.10 max 0.03 max 0.003 0.01 max 0.01 max 0.10 4.8 1.40 0.01

 

Typical Mechanical Properties

Material 0.2 % Yield Strength ksi Ultimate Tensile Strength ksi Elongation in 4D(%)
Maraging 350 330 350 8

 

Available shapes of nickel/cobalt alloy maraging C350：

  • Rods
  • Bars
  • Wires
  • Sheets
  • Plates
  • Forging parts
  • Pipe Fittings
  • Flanges
  • Seamless pipe
  • Seamless tube
  • Welded pipe
  • Welded tube

 

 

Typical application applications of this Maraging C350 include:

  • Tooling
  • Coupling
  • Load cell
  • Munitions
  • Aerospace
  • Die casting
  • Landing gear
  • Extrusion tooling
  • Gears and fasteners
  • Ordnance Mounting Block
  • High performance shafting
  • Missile and rocket engine casings
  • High Performance Racing Components
  • Jet Engines and Helicopter Drive shafts

 

The information, data and specifications provided here are for informational purposes only and are not guaranteed values. The materials or product applications described are for illustration purposes only and should not be construed as an express or implied warranty of suitability for these or other applications.

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