Duplex 2507(UNS S32750 W.Nr.1.4410)

1.Duplex 2507 INTRODUCTION

 2507 is a super duplex stainless steel with higher alloy content, thus making it superior to 2205 in corrosion resistance and strength. It has excellent resistance to uniform, pitting, crevice corrosion and chloride stress corrosion cracking. In dilute sulfuric acid contaminated with chloride ions, 2507 has better corrosion resistance than 904L, which is specially designed to resist pure sulfuric acid. Because 2507’s low carbon content greatly lowers the risk of carbide precipitation at the grain boundaries during heat treatment, it is highly resistant to carbide-related intergranular corrosion. 2507 is not suitable for Applications which require long exposure to temperatures above 300℃ because of the increased risk of a reduction in toughness. Its yield strength is about twice that of conventional austenitic stainless steels.

2.Duplex 2507 GRADE

 Chemical processing industry piping, vessels and heat exchangers; desalination plant seawater piping; oil and gas industry equipment; power plant flue gas desulfurization systems, scrubber systems and absorber towers; and chemical tankers.

6.Duplex 2507 CORROSION PROPERTIES

1. General corrosion

The high chromium and molybdenum content of SAF 2507 makes it more resistant to organic acids such as formic acid and acetic acid, etc. The SAF 2507 alloy is also more resistant to inorganic acids, especially those containing chlorides.

Compared to 904L, SAF2507 is more resistant to dilute sulfuric acid mixed with chloride ions. 904L is an austenitic state alloy and is designed to resist pure sulfuric acid corrosion.

SAF2507 can be used in dilute hydrochloric acid environment, and has strong resistance to spot damage and crevice corrosion.

2. Intergranular corrosion

The low carbon content of SAF 2507 greatly reduces the risk of carbide precipitation in intergranulars during heat treatment, so the alloy has strong resistance to carbide-related intergranular corrosion.

3. Stress corrosion cracking

The complex structure of SAF 2507 gives it a high resistance to stress corrosion cracking. Due to its high alloy content, SAF 2507 has better corrosion resistance and strength than 2205.