The stainless steel grade 310S is a moderate austenitic stainless steel widely used in the elevated temperature operations like furnace components and heat processing systems. It is utilized at temperatures about 1150oC in continuous operations and 1035oC in intermittent operations. The 310S grade is a steel comprising of low concentration of carbon.
The popular uses of stainless steel 310S in the fluidsed bed combustors, furnaces, radiant vessels, vessel hanger for petroleum processing and steam boiler, coal gasifier, internal parts, lead pots, thermowells, refractory anchot bolts, food processing systems, annealing covers and cryogenic configurations.
The stainless steel 310S consists of 25% chromium, 20% nickel that makes it widely resistant to oxidation and corrosion. Its nominal carbon content, less inclined to embrittlement and sensitization while in operation. The large content of chromium and nickel make the steel suitable for the operation in the reducing sulfur. These are extensively used in carburizing conditions as found in petrochemical conditions. For the rigorous carburizing conditions other heat resistant alloys are chosen. The stainless steel 310S is suggested to use for rapid liquid cooling as it may get the heat stroke. It is commonly used in the cryogenic applications for its hardness and lower magnetic permeability.
Just like other stainless steel alloys, this steel can not be toughened by heat processing. It can be toughened by cold processing, though this is rarely used. The chemical composition of stainless steel 310S is shown as following:
|Elements||310 steel||310S steel|
|C||0.25 max||0.08 max|
|Mn||2.00 max||2.00 max|
|Si||1.50 max||1.50 max|
|P||0.045 max||0.045 max|
|S||0.030 max||0.030 max|
|Cr||24.00 – 26.00||24.00 – 26.00|
|Ni||19.00 – 22.00||19.00 – 22.00|
The mechanical features of stainless steel 310S are shown as following:
|Grade 0.2 % Proof Stress MPa (min)||205|
|Tensile Strength MPa (min)||520|
|Elongation % (min)||40|
|Hardness (HV) (max)||225|
The physical properties of stainless steel 310S are provided below:
|Electrical Conductivity||25oC||1.25 %IACS|
|Electrical Resistivity||0.78 Micro ohm.m|
|Modulus of Elasticity||200 GPa|
|Shear Modulus||77 GPa|
|Specific Heat||500 J/kg.°C|
|Relative Magnetic Permeability||1.02|
|Thermal Conductivity||100oC||14.2 W/m.°C|
|Coefficient of Expansion||0-100°C||15.9 /°C|
The fabrication of stainless steel 310S forged in temperature at 975 to 1175oC. The heavy processing is carried out to 1050oC and light finish is done to the bottom of range. Subsequent to forging annealing is suggested to relieve the stress from the forming process. The alloy can be readily cold processed by the standard methods and device.
The machinability of stainless steel 310S alloy is identical to the machining of 304. The process of toughening may cause an issue and it is general to remove the work toughened surface by using nominal speed and massive cuts with the sharp equipments and better lubrication. The strong machines and massive rigid tools are utilized.