TP310 VS TP310S VS TP310H
Stainless steel grades-TP310/TP310S/TP310H performance and characteristics
Introduction of TP310/TP310S/TP310H stainless steel
TP310 stainless steel (UNS S31000) and its derivatives have both excellent high temperature performance, good ductility and weldability.
The carbon content of TP310H stainless steel (UNS S31009) is limited to the lower limit of the range of 310 carbon content, which is a suitable grade for high temperature applications.
When the application environment temperature range is lower than the so-called "high temperature" and there are wet corrosives, TP310S stainless steel (UNS S31008) is used. Compared with TP310H stainless steel, the lower carbon content of TP310S stainless steel does reduce its high temperature strength.
TP310L is a series of patented grades, usually with a maximum carbon content of 0.03%, and is sometimes used in very special corrosive environments, such as urea production.
Like other austenitic stainless steels, the TP310 series has excellent toughness and maintains good toughness even at low freezing temperatures.
| TP310/TP310STP/310H performance and characteristics |
Corrosion resistance
The high chromium content-aimed at improving high temperature performance-also makes these grades have good corrosion resistance to aqueous solutions. PRE is about 25, seawater corrosion resistance is about 22°C, similar to TP316 stainless steel. In high-temperature use environments, they show good resistance to oxidation and carburization. Tolerates fuming nitric acid at room temperature and molten nitrate up to 425°C.
With the exception of TP310L stainless steel, the high carbon content of all grades does make them susceptible to sensitization, so intergranular corrosion is prone to occur after high temperature exposure or welding.
TP310 stainless steel may have stress corrosion cracking, but its stress corrosion resistance is better than TP304 or TP316 stainless steel.
Heat resistance
TP310H stainless steel has good oxidation resistance and can be used intermittently in air with a temperature of up to 1040°C and continuous use in an environment with a temperature of up to 1150°C. Has good resistance to thermal fatigue and cyclic heating performance. Widely used in high temperature sulfur dioxide gas environment. Due to the precipitation of carbides, if there is a subsequent requirement for the corrosion resistance of the material in aqueous solution, it is not recommended to use it continuously in the temperature range of 425-860°C, but it usually performs well above and below this temperature range . In the temperature range of 650-900℃, sigma phase embrittlement easily occurs.
The service temperature of TP310H stainless steel is usually above 800 or 900 ℃-higher than the effective use temperature of TP304H and TP321.
Heat treatment
Solution treatment (annealing)
Heat to 1040-1150°C and cool quickly to obtain maximum corrosion resistance. Due to the precipitation of the σ brittle phase for a long time, it is recommended to perform solution treatment after every 1000 hours of use at a temperature above 650°C to restore ductility.
These grades cannot be hardened by heat treatment.
Welding performance
Good welding performance, suitable for all standard welding methods. For fusion welding, TP310S stainless steel electrode is usually recommended. The specification pre-assessed the welding of TP310 stainless steel with TP310 electrode.
"Double Brand Certification"
TP310H and TP310S are usually produced in the form of "dual certification"-mainly used for sheet and pipe. The chemical and mechanical properties of the material meet both the requirements of the TP310H and TP310S specifications. Materials that only comply with TP310 or TP310/TP310S dual certification may have a carbon content of less than 0.04%, making them unsuitable for certain high temperature applications.
Application
Furnace accessories, fuel oil furnace parts, carburizing boxes, heat treatment baskets and fixtures, heat exchangers, welding filler wires and electrodes, etc.
Performance data specified in standard specifications
ASTM A240/A240M (310S and 310H) and ASTM A 167 (310) stipulate the properties of flat rolled products (medium and thick plates, plates and coils). For other products such as pipes and bars of corresponding specifications, similar but not necessarily identical characteristics are specified.
Chemical composition
Mechanical properties
Physical properties (annealed state)
Equivalent grade
Possible alternative grades
TP304H stainless steel - applications requiring heat resistance, but limited to 800°C.
TP321 stainless steel - applications that require heat resistance and subsequent corrosion resistance to aqueous solutions, but only at 900°C.
253MA stainless steel - requires a slightly higher temperature resistance than 310, better resistance to reducing sulfide, and is not likely to occur in σ phase embrittlement applications.
