Should I choose a stainless steel 310H valve or a stainless steel 310S valve?
Stainless steel 310H valves (UNS S31009 valves) and stainless steel 310S (UNS S31008 valves) valves belong to the austenitic heat-resistant stainless steel series. The main difference lies in the carbon content and high temperature performance, so the application areas are different. The following are its main application areas and detailed descriptions:
1. Differences in valve composition and performance between stainless steel 310H valves (UNS S31009 valves) and stainless steel 310S (UNS S31008 valves)
Advantages of stainless steel 310H valves (UNS S31009 valves):
① Carbon content of stainless steel 310H valves: 0.04–0.10% (enhanced high temperature strength);
② High temperature performance of stainless steel 310H valves: strong creep resistance and high lasting strength;
③ Weldability of stainless steel 310H valves: be cautious (high carbon can easily lead to sensitization);
Advantages of stainless steel 310S valves (UNS S31008 valves):
① Carbon content of stainless steel 310S valves: ≤0.08% (better corrosion resistance);
② High temperature performance of stainless steel 310S valves: good oxidation resistance, but low high temperature strength;
③ Weldability of stainless steel 310S valves: Easier to weld (low carbon reduces carbide precipitation)
2. Comparison of application fields of stainless steel 310H valves (UNS S31009 valves) and stainless steel 310S valves (UNS S31008 valves)
Typical application scenarios of stainless steel 310H valves (UNS S31009 valves) are high-temperature pressure-bearing parts, such as:
① Petrochemical industry: cracking furnace tubes, converter parts (need to withstand high temperature + stress).
② Power industry: boiler burners, superheater tubes (operating temperature can reach 1100°C).
③ Heat treatment equipment: high-temperature furnace rollers, muffle tanks (need to resist creep).
So the key requirement for selecting stainless steel 310H valves should be: maintaining structural strength in long-term high temperature environments (such as >800°C).
The typical application scenarios of stainless steel 310S (UNS S31008 valves) valves are oxidation-resistant but low-stress environments, such as:
① Food industry: oven liner, baking mold (resistant to high temperature oxidation, no need for high mechanical strength).
② Chemical containers: corrosive medium storage tanks (low carbon reduces the risk of intergranular corrosion).
③ General heat-resistant parts: heat exchanger pipes, flue linings (temperature ≤1000°C).
Therefore, the key requirements for selecting stainless steel 310S valves should be: corrosion resistance, easy molding or welding, and low high-temperature stress scenarios.
3. Stainless steel 310H valves (UNS S31009 valves) and stainless steel 310S valves (UNS S31008 valves) selection recommendations:
① Choose stainless steel 310H valves: when the equipment needs to withstand mechanical loads for a long time at high temperatures (such as furnace tubes, supports).
② Choose stainless steel 310S valves: when oxidation/corrosion resistance is the main factor, or welding processing is required (such as containers, non-pressure-bearing parts).
Note: Under extremely high temperatures (>1000°C), the oxidation resistance of stainless steel 310H valves and stainless steel 310S valves is similar, but the strength advantage of 310H is more significant.
Summary
The difference between stainless steel 310H valves and stainless steel 310S valves is essentially the choice of "strength first" and "corrosion resistance/process first", which needs to be determined according to the temperature, stress and processing requirements of specific working conditions.
