CENTRAVIS works closely with customers to better understand any products they may require. Recently CENTRAVIS worked closely with a chemicals producer and learned that the production of caustic soda is related to highly aggressive media, and heat exchanger tubes used in the process must be able to withstand pitting, inter-crystalline corrosion and stress corrosion cracking in high temperature conditions. For many companies this remains a challenge, as premature corrosion leads to increased maintenance costs.
For instance, operational tests of the austenitic 321 grade tubes used by the producer have shown that the material was subject to significant localized corrosion with depths over 0.8 mm, leading to malfunctioning of the heat exchangers.
In order to improve performance of the existing heat exchanger tubes CENTRAVIS has developed a novel technology of double quenching of the material (02?22?5??3, a Russian analogue to duplex 1.4462/UNS S31803), and in 2014 initiated five-months long corrosion testing, which has proven that the material has superior performance against all types of corrosion, as well as excellent mechanical properties.
Heat exchanger tubes of this duplex steel manufactured by CENTRAVIS would allow producer (customer) to decrease both direct (regular replacement of the tubes) and indirect (repairs and idle times affecting productivity) costs due to significantly higher (2.8 to 2.9 times) corrosion resistance of the material.