Sep 26 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Welding
Hot Working
Cold Working
Annealing
Aging
Tempering
Hardening
Applications
Introduction
Stainless steels are called as high-alloy steels. Due to the
presence of large amounts of chromium in the range of 4 to 30%, they
have high corrosion resistance than other steels. Stainless steels are
classified into martensitic, ferritic and austenitic based on their
crystalline structure. However, stainless steels present in the form of
a combination of martensitic and austenitic steels are known as
precipitation-hardened steels.
The following datasheet will provide more details about grade 355
stainless steel.
Chemical Composition
The following table shows the chemical composition of grade 355
stainless steel.
| Element |
Content
(%) |
Iron, Fe
|
73.53 - 77.33
|
| Chromium, Cr |
15 - 16 |
| Nickel, Ni |
4 - 5 |
| Molybdenum, Mo |
2.5 – 3.5 |
| Carbon, C |
0.10-0.15 |
| Manganese, Mn |
0.5-1.25 |
| Silicon, Si |
0.5 |
| Phosphorous, P |
0.04 |
| Sulfur, S |
0.03 |
Physical Properties
The physical properties of grade 355 stainless steel are given in
the following table.
| Properties |
Metric |
Imperial |
| Density |
7.7 – 8.03 g/cm3 |
0.278 – 0.290 lb/in³ |
Mechanical Properties
The mechanical properties of grade 355 stainless steel are displayed
in the following table.
| Properties |
Metric |
Imperial |
| Elastic Modulus |
190 – 210 GPa |
27557 – 30458 ksi |
| Poisson's Ratio |
0.27 – 0.30 |
0.27 – 0.30 |
Other Designations
Other designations that are equivalent to grade 355 stainless steel
include the following:
- AMS 5547
- AMS 5549
- AMS 5743
- AMS 5744
- AMS 5780
- ASTM A564
- ASTM A579
- ASTM A693
- ASTM A705
- SAE J467 (AM-355)
- MIL S-8840
Fabrication and Heat Treatment
Machinability
Adequate lubricant, positive feeds, slow speeds and sharp tooling
are preferred for machining grade 355 stainless steel.
Welding
Grade 355 stainless steel can be welded using all common welding
methods except oxyacetylene welding. The weld piece should be annealed
after welding in order to attain maximum properties. A filler metal of
similar composition can be used at high temperatures to obtain best
results.
Hot Working
Hot working of grade 355 stainless steel can be performed after
heating to 1177°C (2150°F) followed by slowly reducing the temperature
to 982°C (1800°F).
Cold Working
Grade 355 stainless steel can be cold worked in the annealed
condition. This alloy can tolerate only mild forming/deformation in the
hardened condition.
Annealing
Grade 355 stainless steel can be annealed at 1010 to 1066°C (1850 to
1950°F) and then quenched rapidly.
Aging
Aging of grade 355 stainless steel can be performed at 732 to 760°C
(1350 to 1400°F) followed by cooling to room temperature. The alloy is
again aged at 440 to 468°C (825 to 875°F) for 3 hours and then air
cooled.
Tempering
Grade 355 stainless steel can be tempered at 454°C (850°F) to attain
maximum strength or 538°C (1000°F) to attain maximum corrosion
resistance and toughness.
Hardening
Grade 355 stainless steel can be hardened by either sub zero or
double aging methods. However, the alloy has to be rapidly cooled from
932°C (1710°F) before hardening.
Applications
The following are the major applications of grade 355 stainless
steel.
- Industrial cutters and knives
- Valve and gas turbine components