253MA is a grade combining excellent service properties at high temperatures with ease of fabrication. It resists oxidation at temperatures up to 1150°C and can provide superior service to Grade 310 in carbon, nitrogen and sulphur containing atmospheres.
Another proprietary designation covering this grade is 2111HTR.
253MA contains fairly low nickel content, which gives it some advantage in reducing sulphide atmospheres when compared to high nickel alloys and to Grade 310. The inclusion of high silicon, nitrogen and cerium contents gives the steel good oxide stability, high elevated temperature strength and excellent resistance to sigma phase precipitation.
The austenitic structure gives this grade excellent toughness, even down to cryogenic temperatures.
These properties are specified for flat rolled product (plate, sheet and coil) as Grade S30815 in ASTM A240/A240M. Similar but not necessarily identical properties are specified for other products such as pipe and bar in their respective specifications.
Typical compositional ranges for grade 253MA stainless steels are given in table 1.
Table 1. Composition ranges for 253MA grade stainless steel
C |
Mn |
Si |
P |
S |
Cr |
Ni |
N |
Ce |
|
min. | 0.05 | - | 1.10 | - | - | 20.0 | 10.0 | 0.14 | 0.03 |
max. | 0.10 | 0.80 | 2.00 | 0.040 | 0.030 | 22.0 | 12.0 | 0.20 | 0.08 |