SS 301 is a austenitic chromium-nickel steel. 301 Stainless steel is cold rolled and found in different grades – 1/2 hard , 1/4 hard , 3/4 hard and full hard. In this article I am very much keen to discuss about the SS 301 full hard. SS 301 is not magnetic when annealed but it becomes magnetic after cold working. It is available in the market in different conditions such as annealed as well as various temper-rolled condition.
301 SS is named differently in different standards. It is known as
· AISI – 301
· ASTM – A167 and ASTM – A177
· ASTM A666
· DIN 1.4310
· MIL S-5059
· UNS S30100
· QQ S766
· ASTM A554
301 is a austenitic SS having optimum amount of chromium and nickel. 301 is a product derived from SS 304 . The process is to reduce chromium and nickel content. As a result –
· the cold hardening range of the steel is improved.
· higher tensile strength ensured with very little loss of ductility.
· the grade becomes more magnetic than other forms of standard austenitic steels though it is totally non-magnetic when annealed.
· It becomes suitable for forming.
· Fatigue life increases.
· Can be used a flat plate spring material.
SS 301 full hard can be got in different dimensions in accordance with the scope of the manufacturer. Here is the chemical composition by weight of 301 Stainless Steel .
· Carbon – 01.5 maximum
· Phosphorus – 0.045 maximum.
· Manganese – 2.00 Maximum.
· Silicon – 0.75 Maximum
· Sulfur – 0.030 maximum
· Chromium – 16.00-18.00
· Nitrogen – 0.10 maximum
· Nickel – 6.00-8.00
· Iron – to be balanced
Please note that this composition is based on weight percentage.
The Table – 1 represents mechanical properties of full hard 301 stainless steel at room temperature
Table – 01
Heat Treatment Condition | Ultimate Strength (UTS) ksi (MPa) | 0.2 % Yield Strength ksi (MPa) | Elongation % in 2” (50.8 mm) | Rockwell Hardness Number |
Annealed | 120 (ksi) or 827 (MPa ) | 45 (ksi) or 310 (MPa ) | 60 | B86 |
Table -02 represents the cold work properties of the SS 301 Full hard
Table -02
Heat Treatment Condition | Ultimate Strength (UTS) ksi (MPa) | 0.2 % Yield Strength ksi (MPa) | Elongation % in 2” (50.8 mm) | Rockwell Hardness Number | |
≤ 0.0015 in | ≥0.0015 in | ||||
Full Hard | 185 ksi or 1276 MPa | 140 ksi or 965 MPa | 9 | 9 | C 41 |
Table -03 Shows Full hard steel sheet properties with increased temperatures
Temperature degree F or degree Celcius | Ultimate Strength (Mpa) | 0.2% Yield Strength (MPa) | Elongation percentage in 2 inches (50.8 mm) |
Room temp | 1276 | 1041 | 9.0 |
200 or 93 | 1200 | 1000 | 7.0 |
400 or 204 | 1158 | 965 | 4.5 |
600 or 316 | 1076 | 896 | 6.0 |
800 or 427 | 1000 | 820 | 6.0 |
Table – 04 Shows the low temperature mechanical properties of SS 301 full hard
Table – 05 – Impact Energy Chart of Stainless Steel 301 Full Hard
Explanation : The graph indicates that for both ultimate and yield strength there is significant changes with the cold work reduction percentage.
Figure – 02 Changes in the hardness and elongation with the cold work reduction percentage
Have a look at this chart for basic physical properties of 301 Stainless Steel
Corrosion Resistance : SS 301 full hard has excellent corrosion resistance properties in comparison to 304 and 302. Resistance to atmospheric corrosion is superb. The optimum corrosion resistance can be got by cold working rather than annealing.
Oxidation Resistance: The 301 SS can be exposed up to a temperature of 1600 degree Fahrenheit. And at this temperature no scaling is needed.
Heat Treatments : Annealing can be done to SS 301 for hardening. At first the steel can be heated to 1900 – 2050 degree Fahrenheit. Then water quenching is done. After that for stress relieving the materials is heated to 500 – 900 degree Fahrenheit. Then the material is cooled in air.
Cold Working: SS 301 is cold worked to achieve desirable hardness and strength.
Formability: SS 301 is ready for instant forming and drawing process. Sometimes forming process for this material is tough where multiple forming methods are necessary.
Weldability: Common fusion and resistance welding is suitable for 301. Sometimes it needs some extra care while welding to avoid hot cracking.