summary:2520 (310S) is often used to describe high-chromium, high-nickel austenitic heat-resistant stainless steel systems, with a core focus on stability and component lifespan under high-temperature oxidizing environments. In high-temperature stainless steel castings, it is suitable for furnace load-bearing components, heat treatment fixtures, and high-temperature conveying parts. This article explains its value from four aspects: grade comparison, casting advantages, typical applications, and procurement selection.
1. What is 2520 (310S) material?
In domestic industry exchanges, "2520" usually refers to a heat-resistant stainless steel material system with approximately 25% of chromium and 20% of nickel. 310S is one of the common low-carbon austenitic heat-resistant stainless steel grades, often corresponding to UNS S31008, EN 1.4845, etc. High chromium content helps to form a protective oxide film in high-temperature oxidizing atmospheres, while high nickel content helps to maintain the stability of the austenitic structure.
It should be noted that:The 310S designation for plate or forging materials cannot directly replace the delivery standard for heat-resistant steel castings.The procurement of castings should be based on drawings, applicable casting standards, chemical composition, heat treatment status, dimensions and inspection requirements to confirm the materials, and avoid selecting materials based solely on common names.
II. Main Advantages of 2520 (310S) High Temperature Resistant Stainless Steel Castings
1. Enhanced high-temperature antioxidant capacity
Compared to commonly used stainless steels such as 304 and 316, 310S has a higher chromium and nickel content, and is designed as a heat-resistant material for high-temperature environments. Under appropriate operating conditions, in air or furnace gases that are primarily oxidizing, it can slow down the loss caused by the rapid formation and peeling of surface oxide scale.
2. It exhibits good tissue stability and load-bearing adaptability at high temperatures.
Furnace hangers, material baskets, furnace bottom plates, and supports must not only be heat-resistant, but also withstand their own weight, workpiece loads, and the risk of deformation caused by prolonged heat preservation. 310S castings can be integrally formed according to the structure, making them suitable for manufacturing complex high-temperature load-bearing components; however, their actual service life should still be assessed in conjunction with wall thickness, load, temperature cycling, and creep design.
3. Suitable for integral casting of complex heat-resistant parts
For components with stiffeners, lugs, holes, guide structures, or irregular flow channels, casting can reduce welding joints and facilitate the formation of complex structures. After proper casting design, heat treatment, and inspection, it is suitable for mass production of furnace tooling and non-standard high-temperature components.
4. The 310S low-carbon design is beneficial for subsequent manufacturing and the control of specific corrosion risks.
Compared to heat-resistant steels in the same series with higher carbon content, the low carbon content of 310S helps reduce the risk of sensitization in certain welding or shutdown condensation corrosion scenarios. Therefore, 310S is often a worthwhile option to evaluate for components that require both high-temperature oxidation resistance and involve welding repairs, assembly, or repeated temperature changes.
III. How to choose 310S compared to other commonly used stainless steel grades?
| Comparison of brands | Main features | Selection focus compared to 2520 (310S) |
|---|---|---|
| 304 / 304L | Good versatility and relatively easy cost control | 310S is commonly used in normal and low-temperature corrosion conditions; however, it is more suitable for continuous high-temperature oxidation scenarios. |
| 316 / 316L | Molybdenum-containing compounds are more advantageous against certain wet corrosive media. | Suitable for applications requiring resistance to corrosion in liquid media; high-temperature furnace oxidation resistance is not its primary focus. |
| 309S | Both belong to heat-resistant austenitic stainless steel | When temperature and oxidation requirements are further increased, and the design allows, 310S with higher chromium-nickel configurations can be evaluated. |
| 310 / 310S | Both belong to the high-chromium, high-nickel heat-resistant system | The 310S employs lower carbon emissions control, making it suitable for components where welding manufacturing and related sensitization risks need to be considered; specific standards and operating conditions shall prevail. |
| Heat-resistant cast steel special grade | Designed for creep, carburizing, or special furnace gases | Under harsh loads or special atmospheres, the designation should not be compared solely based on name; it should be determined jointly by materials engineering and casting solutions. |
in short,The advantage of 310S lies not in replacing all stainless steels, but in its clear material positioning under high-temperature oxidation conditions.Special environments such as those containing sulfur, carburizing, molten salt, strongly reducing atmospheres, or high mechanical loads require separate material verification.
IV. Where are 2520 (310S) high-temperature resistant stainless steel castings mainly used?
- Industrial furnaces and heat treatment equipment:Material trays, material baskets, furnace bottom plates, guide rails, fan blades, furnace door components, hanging fixtures, brackets, and radiant tube supports.
- Metallurgical and non-ferrous metals industry:High-temperature conveying components, furnace bearing components, and heat-resistant components related to heating furnaces and annealing lines.
- Petrochemical and Energy Equipment:Support components near high-temperature flue gas, heat-resistant components related to heat exchange equipment, and protective components for thermal instruments.
- Cement, ceramics, and calcination production lines:Heat-resistant fasteners, brackets, and high-temperature conveying accessories around the kiln.
- Non-standard mechanical equipment components:Requires complex structure, oxidation resistance and thermal cycling adaptabilityPrecision castingOr sand casting parts.
V. Key parameters to confirm when purchasing 310S high-temperature resistant castings
- Actual maximum and continuous operating temperatures:The impact of short-term peak temperature and long-term operating temperature on material selection is different.
- Composition of furnace gas or medium:Oxidation, reduction, sulfur-containing, carburizing, and hot and cold cycling environments cannot be simply equated.
- Loads and Structure:Confirm the wall thickness, reinforcing ribs, support method, deformation allowance, and service life target.
- Material acceptance criteria:Clearly define the requirements for chemical composition, casting standards, heat treatment, dimensional tolerances, and spectral or mechanical property testing.
- Manufacturing and Quality Control:The requirements for appearance, dimensions, non-destructive testing, and trial assembly are agreed upon based on the importance of the components.
VI. Frequently Asked Questions (FAQ)
Are 2520 and 310S the exact same grade?
“"2520" is a common industry term for the 25Cr-20Ni heat-resistant material system, while 310S is one of the specific standard grade expressions. For castings, the composition, standards, and inspection documents agreed upon in the contract should be the final basis.
What temperature range can 310S castings be used for extended periods?
Material supplier documentation typically positions 310S for high-temperature applications exceeding approximately 550°C and indicates its suitability for even higher temperatures in oxidizing environments. However, the permissible operating temperature of castings cannot be determined solely by furnace gas, load, thermal cycling, structural dimensions, and lifespan requirements; each factor must be verified individually during engineering selection.
Why are 310S castings considered for furnace tooling?
Furnace tooling often requires oxidation resistance, complex structural forming, and high-temperature dimensional stability. The high chromium and high nickel heat resistance of 310S, combined with casting processes, can cover the design requirements of many trays, hangers, supports, and furnace accessories.
Conclusion
The core value of 2520 (310S) high-temperature resistant stainless steel castings lies in providing more targeted material selection for complex furnace and equipment components in high-temperature oxidation and thermal cycling environments. The correct approach is not to simply pursue the grade, but to incorporate temperature, atmosphere, load, structural design, and inspection requirements into the selection process. When custom-made heat-resistant stainless steel castings are needed, providing operating conditions, drawings, and acceptance requirements helps to determine the appropriate material and manufacturing solution more quickly.
