13Ni Expansion steel S131
2026-08-03 11:12:26   Origin：   Remark：0 Click：

Type BS S131 is defined as a Fe - 12.5Ni - 4.5Mn - 3.5Cr - 0.6C austenitic type steel with a high thermal expansion, fastener material used for assembly of light alloy components working at high temperatures.

Technical specification: MSRR6616, BS EN 3890-2002
Steel category: Fe base - 12.5Ni - 4.5Mn - 3.5Cr - 0.6C alloy steel
HS Code: 72284000 / 7228 5000
Heat treatment: 1040℃ solution treated.

TYPICAL CHEMICAL ELEMENTS (mass fraction - %)
Carbon, C (％): 0.55 ~ 0.70
Silicon, Si (％): 0.20 ~ 0.50
Manganese, Mn (％): 3.50 ~ 5.50
Phosphorus, P (％): ≤ 0.035
Sulfur, S (％): ≤ 0.025
Chromium, Cr (％): 3.00 ~ 4.00
Nickel, Ni (％): 11.0 ~ 14.0
Molybdenum, Mo (％): ≤ 0.50
Niobium, Nb/Ti (%): - 
Others (％): tungsten, W ≤ 1.00, vanadium, V ≤ 0.25
Ferrum, Fe (%): balance.

TYPICAL MECHANICAL PROPERTIES
Heat treatment condition: 1020 ℃ solution annealed
Tensile strength, Rm ≥ MPa: 620
Yield strength, Rp0.2 ≥ MPa: 300
Elongation, A5 ≥ (%): 35.0
Impact strength, AKU ≥ J:  -
Hardness HBS: -
Condition: work hardened
Tensile strength, Rm ≥ MPa:  950
Yield strength, Rp0.2 ≥ MPa: 740
Elongation, A5 ≥ (%): 30
Impact strength, AKv ≥ J: -
Hardness HBS: -

TYPICAL APPLICATIONS
S131 displays a good feature with a coefficient of expansion close to that of aluminum. Its mechanical properties can be enhanced by thermal treatment and further step by work hardening.
Fasteners used for assembly of light alloy components working at high temperatures. 
Distribution hollow tubes for valveless engines with pistons and cylinders. 
Precombustion chambers fitted to light alloy piston heads for diesel engines.