Description

UDIMAR® alloy 300 (UNS K93120)

Table 1 – Limiting Chemical Composition, %

 

hardenable (maraging) iron-nickel steel combining                                                                                                            

 

ultra-high strength, toughness and resistance to crack propagation. The alloy is well suited to applications where heat treatment distortion and dimensional changes must be minimized and where high fracture toughness is required, such as rocket motor casings, light aircraft landing gear, power shafts and low temperature tooling.

The 18% nickel maraging steels offer a unique combination of properties not available from conventional low alloy ultra-high strength steels. They offer high strength, high ductility and toughness, and resistance to crack propagation. Hardening is accomplished by a simple aging cycle of 3 hours at 900°F (482°C) followed by air cooling.

300 provides through hardening without quenching, freedom from decarburization, minimal distortion during aging, good formability, machinability, and weldability and a low coefficient of thermal expansion.

 

 

Available Products and Specifications

UDIMAR alloy 300 is designated UNS K93120 and is available as forging billet and bar.

Major specifications:   AMS 6514

 

 

Typical Mechanical Properties

Carbon………………………………………………………….. 0.03 max.

Silicon…………………………………………………………… 0.10 max.

Manganese……………………………………………………. 0.10 max.

Sulfur…………………………………………………………… 0.010 max.

Phosphorus…………………………………………………. 0.010 max.

Cobalt……………………………………………………………….. 8.0-9.5

Nickel……………………………………………………………. 18.0-19.0

Molybdenum………………………………………………………. 4.6-5.2

Titanium…………………………………………………………. 0.55-0.80

Aluminum……………………………………………………….. 0.05-0.15

Iron………………………………………………………………… Balance*

 

*Reference to the ‘balance’ of a composition does not guarantee this is exclusively of the element mentioned but that it predominates and others are present only in minimal quantities.

 

 

Physical Constants

Table 2 – Physical Constants

Density, lb/in³……………………………………………………….. 0.290

g/cm³…………………………………………………………… 8.0

Melting Range, °F………………………………………….. 2600-2650

°C………………………………………….. 1427-1454

Specific Heat, Btu/lb•°F………………………………………….. 0.08

J/kg•°K……………………………………………… 335

Permeability at 200 Oersted (15.9 kA/m)…………………….. 77.5

Coefficient of Expansion, 70-200°F, 10^-6 in/in•°F…………… 4.8

21-93°C, µm/m•°C………………. 8.64

Thermal Conductivity, Btu•in/ft²•h•°F…………………………. 136

W/m•°C…………………………………. 19.6

 

Table 3 – Typical Mechanical Properties of UDIMAR alloy 300

 

	Solution Annealed 1500°F (816°C), 1 hr, AC	Solution Annealed Plus Aged 900°F (482°C), 3 hrs, AC
0.2% Yield Strength, ksi	120	280
Ultimate Tensile Strength, ksi	150	290
Elongation, %	16	8
Reduction of Area, %	70	40
Hardness, Rc	30	52

 

 

Publication Number SMC-110

Copyright © Special Metals Corporation, 2004 (Sept 04)

 

UDIMAR is a trademark of the Special Metals Corporation group of companies.