Problems with intergranular corrosion testing

Graphite heat exchangers are recommended for use under process conditions involving chloride ions. Under conditions of high temperature and high chloride ion concentrations, the corrosion rate of 316L steel is very high; in such situations, graphite heat exchangers demonstrate their excellent corrosion resistance. Graphite heat exchangers can be used for a long time at the boiling point of hydrochloric acid at any concentration without experiencing corrosion.

Since the medium contains chloride ions, it is not recommended to use stainless steel heat exchangers made of 316L material.

Although it is 316L steel, which has a lower carbon content and thus a reduced risk of intergranular corrosion, it is still not recommended for use as a heat exchanger when the medium contains chloride ions. Chloride ions cause the most severe corrosion of stainless steel; therefore, 316L is not suitable, and duplex steel is a better choice than 316L.

Using 316L in the presence of chloride ions is not appropriate; chloride ions cause stress corrosion and pitting in austenitic stainless steels, and it is also ineffective for intergranular corrosion tests. It is recommended to consider using duplex steel; for applications with high chloride content, titanium alloy is a better choice.

Whether to use TP316L depends on the chloride content in the medium. TP316L contains molybdenum, and theoretically it can be used in chlorine-containing environments, offering a certain level of corrosion resistance. However, when used in seawater or brackish water, it is recommended to opt for other types of stainless steel such as super austenitic materials or duplex steels. SS316L can be subjected to intergranular corrosion tests; if following American standards, method E of A262 can be used as the standard for such tests

Hello, our company is a specialist in the sales of stainless steel products, which are widely used in industries such as petroleum, chemicals, power generation, and machinery. The standard pipe fittings available include: stainless steel pipe fittings, stainless steel elbows, stainless steel reducers, stainless steel tees, stainless steel flanges, stainless steel crosses, butt-welded elbows, and more – with over 1,000 different specifications. The product features anti-corrosion properties, resistance to acids and alkalis, a long service life, a smooth surface, resistance to acids, alkalis, and high temperatures. It offers a reasonable price, an attractive appearance, and excellent quality. Manufacturing standards: national standards, American standards, Russian standards, Japanese standards, etc. The materials include 304, 304L, 321, 316, 316L, 310S, 2205, 2507, and various other materials. We are committed to retaining existing customers and acquiring new ones through excellent after-sales service, competitive prices, a wide range of products, and reliable delivery times. Contact: Manager Shi, 13313077236.