Heat-resistant steel
Austenitic steels, such as stainless steel grade 1.4828, have a thermal conductivity only 30% of that of non-alloyed steels. Their melting points are lower than non-alloyed steels, so the welding heat input for austenitic steels must be lower than for non-alloyed steels. This grade is suitable for components requiring scale resistance up to approximately 1000 °C. Material 1.4828 can be weakly magnetized in the quenched state. The magnetic susceptibility increases with increasing cold deformation.
Chemical Composition:
C：1.00~1.10
Si：≤1.00
Mn：≤1.00
P：≤0.045
S：≤0.030
Cr：12.00~14.00
Mo：0.40~0.60
Physical Properties:
Tensile strength, R m : 550 – 750 MPa
Yield point, R e : > 230 MPa
Elongation, A: >28%
Hardness: < 223 HB
Modulus of elasticity, E = 196 GPa
Heat capacity, c p20-100℃ = 500 J * kg -1 * K -1
Thermal conductivity, λ = 15.0 W * m -1 * K -1
Linear expansion coefficient, α p20-100℃ = 16.5 – 19.5 * 10 -6 K -1
Corrosion Resistance
1.4828 (309) High-quality stainless steel material resistant to calcification up to 1050 C in oxidizing environments. 1.4828 steel is sensitive to SO2, especially to gases containing H2S.
Additionally, it has some sensitivity to carbonizing gases, especially at temperatures above 900oC. Grade 309 stainless steel tends to become brittle due to the formation of the Sigma phase when operated continuously in the temperature range of 600 to 850°C.
Solderability
Most austenitic stainless steels can be easily welded using fusion or resistance methods, but diacetylene welding is not recommended.
Filler metal shall be AWS E/ER 309 or 309L.
Processability
309 high-quality alloy type 304 stainless steel is processed the most. It hardens quickly. The tool should always be cutting and a chip breaker should be used.
Cold Working
Quality 1.4828 (309) alloy, although it has a high rate of work hardening, can be drawn, started, distressed and stamped. Complete annealing is required after cold working to eliminate internal stress.
Applied Area
Grade 309 stainless steel, furnace linings, boiler compartments, firebox plates, furnace parts and other high temperature vessels, steam boiler and furnace parts: liners, brackets, air preheater ducts, covers, case hardened vessels.
