201 Stainless Steel
Type 201 Stainless Steel is covered by the following specifications: ASTM A240, ASTM A666.
Chemical Composition:
Element | Type 201 |
Carbon | 0.15x |
Manganese | 5.5 - 7.5 |
Sulfur | 0.03X |
Phosphorus | 0.060x |
Silicon | 1.0 x |
Chromium | 16 - 18 |
Nickel | 3.5 -5.5 |
Nitrogen | 0.25x |
Mechanical Properties:
Type | Yield Strength 0.2% offset (KSI) | Tensile Strength (KSI) |
% Elongation (2" Gauge length) |
Hardness Rockwell |
201 Ann | 38 min. | 75 min. | 40% min. | HRB 95 max. |
201 ¼ Hard | 75 min. | 125 min. | 25.0 min. | 25 – 32 HRC (typical) |
201 ½ Hard | 110 min. | 150 min. | 18.0 min. | 32 - 37 HRC (typical) |
201 ¾ Hard | 135 min. | 175 min. | 12.0 min. | 37 – 41 HRC (typical) |
201 Full Hard | 145 min. | 185 min. | 9.0 min. | 41 – 46 HRC (typical) |
Fabrication
Type 201 Stainless Steel can be fabricated by bench forming, roll forming and brake bending in much the same manner as Type 301. However, because of its higher strength, it may exhibit greaterspringback. This material can be drawn similarly to Type 301 in most drawing operations if more power is used and the hold-down pressure is increased.
Heat Treatment
Type 201 is not hardenable by heat treatment. Annealing: Anneal at 1850 – 1950 °F (1010 – 1066 °C), then water quench or rapidly air cool. The annealing temperature should be kept as low as possible, consistent with the desired properties, because Type 201 tends to scale more than Type 301.
Weldability
The austenitic class of stainless steels is generally considered to be weldable by the common fusion and resistance techniques. Special consideration is required to avoid weld “hot cracking” by assuring formation of ferrite in the weld deposit. As with other chrome-nickel austenitic stainless steel grades where carbon is not restricted to 0.03% or below, the weld heat affected zone may be sensitized and subject to intergranular corrosion in some environments.This particular alloy is generally considered to have poorer weldability to the most common alloy of this stainless class, Type 304L Stainless Steel. When a weld filler is needed, AWS E/ER 308 is most often specified. Type 201 Stainless Steel is well known in reference literature and more information can be obtained in this way.