| 材料等级： | S31803 ， S32750， S32760 ， S31254， S32900， S32304 ， S31500 ， 2205 | Standand: | A789， A790 |
|---|---|---|---|
| 无损检测： | ET，UT，HT，PT | 申请： | SuperHeater/ Heat Exchanger |
| 强光 | Heat Exchanger Duplex Stainless Steel Tube， UNS S31803 Duplex Stainless Steel Tube， Welding Seamless Duplex Steel Pipe | ||
ASTM A789 S31803 (1.4462) SAF2205 Duplex Stainless Steel tube
| 合金 | UNS 编号 | SAE Number |
超级双相 S31803 | UNS S31803 |
GENERAL PROPERTIES
UNS S31803 is a duplex grade with a ferritic-austenitic microstructure. The alloy consists of around 40-50% ferrite in the annealed condition. The duplex microstructure has the high strength of the ferritic grades whilst retaining the corrosion resistance of the austenitic grades. It is not uncommon to see the metal used as a practical solution to chloride-induced stress cracking.
It has superior resistance to chloride pitting and crevice corrosion as compared to 317L stainless steel. The alloy has outstanding corrosion resistance to seawater and most concentrations of sulphuric acid. In addition， it is also resistant to sulphide stress corrosion cracking (sour-gas environments).
RESISTANCE TO CORROSION
UNS S31803 is resistant to intergranular corrosion. It has better corrosion resistance than that of other austenitic stainless grades such as 316， with higher resistance to stress corrosion cracking to that of either 304 or 316 stainless grades. Pitting corrosion and crevice corrosion is higher than that of 316. Due to its higher corrosion resistance UNS S31803 has better fatigue strength in corrosive environments than that of other austenitic stainless steel specifications.
| 熔点 | 密度 | 比重 | 弹性模量 in Tension |
| 1420 – 1465 ℃ | 7.8g/cm3 | 7.8 | 200 GPa |
机械性能
| 合金 | 拉伸强度 最低 (psi) | 屈服强度 Minimum 0.2% offset (psi) | % 延伸 in 2" Minimum |
| S31803 | 90，000 | 65，000 | 25 |
CHEMICAL PROPERTIES
| 合金 | C | Si | 锰 | P | Cr | 倪 | S | N | 莫 |
| S31803 | 0.03 | 1.0 | 2.0 | 0.035 | 21.0-23.0 | 4.5-6.5 | 0.015 | 0.1-0.22 | 2.5-3.5 |
焊接
UNS S31803 (1.4462， F51) has good weldability similar to that of other stainless steel types. Low thermal expansion reduces residual stresses after welding. Use duplex welding electrodes similar to that of the parent steel when welding UNS S31083. Electric arc welding processes are suitable though oxyacetylene welding is not recommended due to the possibility of carbon pick up in the weld area of the UNS S31803. Whilst post weld annealing is not a requirement for many applications it will give optimum corrosion resistance in severe service conditions. We recommend you contact your welding consumables supplier who should provide you full assistance and information of welding UNS S31803 duplex.
热处理
UNS S31803 (1.4462， F51) cannot be hardened by conventional heat treatment， though it is a work hardening steel. Duplex can be solution annealed at 1020-1100ºC， water quench.
