Stainless Steel 450 Alloy (UNS S45000)

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Welding
Hot Working
Cold Working
Annealing
Aging
Applications

Introduction

Stainless steels are high-alloy steels. They contain about 4-30% of chromium. They are classified into three types such as martensitic, austenitic, and ferritic steels. Another group of stainless steels are precipitation-hardened steels. They result from a combination of austenitic and martensitic steels.

Grade 450 stainless steel alloy is a martensitic type stainless steel. It has high ductility and strength. It has a yield strength which is nearly 3 times the strength of grade 304 stainless steel. The following datasheet gives an overview of grade 450 stainless steel alloy.

Chemical Composition

The following table shows the chemical composition of grade 450 stainless steel alloy.

Element Content (%)
Iron, Fe 74.3
Chromium, Cr 15
Nickel, Ni 6
Copper, Cu 1.5
Silicon, Si 1.0
Manganese, Mn 1.0
Molybdenum, Mo 0.75
Niobium, Nb (Columbium, Cb) 0.40
Carbon, C 0.050
Phosphorous, P 0.030
Sulfur, S 0.030

Physical Properties

The physical properties of grade 450 stainless steel alloy are displayed in the following table.

Properties Metric Imperial
Density 7.80 cm³ 0.282 lb/in³

Mechanical Properties

The following table outlines the mechanical properties of grade 450 stainless steel alloy.

Properties Metric Imperial
Tensile strength 986 MPa 143000 psi
Yield strength (@ strain 0.200%) 814 MPa 118000 psi
Bulk modulus (typical for steel) 166 GPa 24100 ksi
Shear modulus (typical for steel) 83.9 GPa 12200 ksi
Charpy impact 125 - 141 J 92.2 - 104 ft-lb
Elongation at break (gage length is 4 times specimen diameter) 13.30% 13.30%
Hardness, Brinell (converted from Rockwell C hardness) 278 278
Hardness, Knoop (converted from Rockwell C hardness) 296 296
Hardness, Rockwell C 28 28
Hardness, Vickers (converted from Rockwell C hardness) 287 287

Thermal Properties

The thermal properties of grade 450 stainless steel alloy are displayed in the following table.

Properties Metric Imperial
Thermal expansion co-efficient ( @ 20-100°C/68-212°F) 10.1 µm/m°C 5.61 µin/in°F
Thermal conductivity (typical value for stainless steel) 20.7 W/mK 144 BTU in/hr.ft².°F

Other Designations

Other designations that are equivalent to grade 450 stainless steel alloy include:

  • AMS 5763
  • AMS 5773
  • AMS 5859
  • AMS 5863
  • ASTM A564 (XM-25)
  • ASTM A693 (XM-25)
  • ASTM A705 (XM-25)

Fabrication and Heat Treatment

Machinability

Grade 450 stainless steel alloy uses feeds and speeds comparable with other martensitic stainless steels. It is preferred to use positive feeds and slow speeds to achieve good results.

Welding

Grade 450 stainless steel alloy can be welded using shielded methods to reduce contamination.

Hot Working

Grade 450 stainless steel alloy can be hot worked by soaking at 1150-1177°C (2100-2150°F) followed by cooling and fully annealing.

Cold Working

Grade 450 stainless steel alloy can be cold worked using all common techniques.

Annealing

Grade 450 stainless steel alloy is annealed by soaking at 1024-1052°C (1875-7925°F) for 1 h followed by quenching in water or oil.

Aging

Grade 450 stainless steel alloy is soaked at specific temperature for 4 h followed by cooling to obtain condition H900, H950, H1000, H1050 or H1150.

Applications

Grade 450 stainless steel alloy is mainly used in applications where martensitics fail in terms of corrosion resistance, and standard austenitics fail in terms of strength requirements in corrosive environments.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit