Degradation of R35 Steel in 5% NaCl environment at 10°C

Abstract. Carbon steels are willingly used due to the favorable price-performance ratio. They usually do not operate in a non-corrosive state. However, there are products that are hard to protect against corrosion in their entirety. These products include pipes. It is easy to protect the outer layer of the pipe against aggressive environment. The problem with protection is caused by their inner surface. Typically, the working medium is the protective factor, usually filling the internal volume of the pipes completely. It happens, however, that corrosion occurs as a result of long storage of pipes in warehouses, usually in the open air. They are also used as working elements with partial liquid filling. They are then exposed to the environment. One of the corrosive agents is NaCl. The paper presents the results of corrosion rate tests of samples taken from R35 pipes in the environment of a 5% aqueous solution of NaCl at 10oC. The analyzes were carried out based on the determination of mass losses. On the basis of the tests carried out, the relationship between the rate of corrosion and the soaking time of the samples was determined. It was confirmed that on the basis of roughness parameters it is possible to draw conclusions about the suitability of steel for further operation.