Sep 24 2012
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 455 stainless steel alloy is a martensitic stainless steel. It possesses a yield strength which is nearly 3 times the strength of grade 304 stainless steel. The following datasheet gives an overview of grade 455 stainless steel alloy.
Chemical Composition
The chemical composition of grade 455 stainless steel alloy is outlined in the following table.
|
Element |
Content (%) |
|
Iron, Fe |
73 |
|
Chromium, Cr |
11.8 |
|
Nickel, Ni |
8.5 |
|
Niobium, Nb (Columbium, Cb) |
2 |
|
Copper, Cu |
2 |
|
Titanium, Ti |
1.1 |
|
Manganese, Mn |
0.50 |
|
Molybdenum, Mo |
0.50 |
|
Silicon, Si |
0.50 |
|
Carbon, C |
0.050 |
|
Phosphorous, P |
0.040 |
|
Sulfur, S |
0.030 |
Physical Properties
The physical properties of grade 455 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 shows the mechanical properties of annealed grade 455 stainless steel alloy.
|
Properties |
Metric |
Imperial |
|
Tensile strength (@ diameter 102 mm/4 in) |
965 MPa |
140000 psi |
|
Yield strength (@ strain 0.200%, diameter 25.4 mm/1 in) |
795 MPa |
115000 psi |
|
Notched tensile strength ( (@ diameter 25.4 mm/1 in) |
1585 MPa |
229900 psi |
|
Charpy Impact |
95 J |
70.1 ft-lb |
|
Elongation at break (@ diameter 102 mm/4 in, in 50 mm) |
12% |
12% |
|
Hardness, Brinell (@ diameter 25.4 mm/ 1 in, converted from Rockwell C hardness) |
297 |
297 |
|
Hardness, Knoop (@ diameter 25.4 mm/ 1 in, converted from Rockwell C hardness) |
318 |
318 |
|
Hardness, Rockwell C (diameter 25.4 mm/ 1 in) |
31 |
31 |
|
Hardness, Vickers (diameter 25.4 mm/ 1 in, converted from Rockwell C hardness) |
308 |
308 |
Thermal Properties
The thermal properties of grade 455 stainless steel alloy are highlighted in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@ 24-150°C/75.2-302°F, when annealed at 1040°C, water quenched) |
10.1 µm/m°C |
5.61 µin/in°F |
|
Thermal conductivity (@ 100°C/212°F) |
18.0 W/mK |
125 BTU in/hr.ft².°F |
Other Designations
Other designations that are equivalent to grade 455 stainless steel alloy include:
-
AMS 5578
-
AMS 5617
-
AMS 5672
-
AMS 5860
-
ASTM A313
-
ASTM A564
-
ASTM A693
-
ASTM A705
-
MIL F-83311
-
MIL S-83311
Fabrication and Heat Treatment
Machinability
Grade 455 stainless steel alloy uses positive feeds and slow speeds to achieve good results.
Welding
Grade 455 stainless steel alloy can be welded using resistance and shielded fusion techniques. After welding, this alloy can be aged to attain good properties.
Hot Working
Grade 455 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 455 stainless steel alloy can be cold worked using all common techniques.
Annealing
Grade 455 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 455 stainless steel alloy can be soaked at a 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.