The substantially expanded publication compares 83 stainless steel grades and provides engineers and designers with a practical tool for selecting materials according to their application requirements.
Choosing the right stainless steel grade requires more than simply comparing corrosion resistance. Strength, formability, weldability and thermal properties can be equally important, depending on the application. This becomes particularly relevant when an existing material grade is to be substituted, as focusing on a single property can result in quality issues or higher costs.
To facilitate a systematic comparison, the second edition of ISER’s Merkblatt 820e evaluates 83 stainless steel grades according to six key material properties: corrosion resistance, strength, formability, weldability, thermal expansion and thermal conductivity. The results are presented in radar charts, allowing users to quickly compare the characteristic property profiles of different grades.
Compared with the first edition published in 2022, which covered 38 grades, the new 2026 edition has been considerably expanded. It now also includes martensitic as well as high-temperature and heat-resistant stainless steels. The grades covered are grouped into martensitic, austenitic, austenitic-ferritic and ferritic stainless steels.
Material selection according to Eurocode 3
A major addition to the second edition is guidance on material selection and durability according to Eurocode 3, specifically DIN EN 1993-1-4, Annex A. While the procedure defined by the standard applies primarily to load-bearing components in construction, ISER points out that the approach can also provide general guidance when selecting stainless steels with regard to corrosion exposure.
The guideline explains how the Corrosion Resistance Factor (CRF) and the corresponding Corrosion Resistance Class (CRC) can be determined and used as part of the selection process. Separate sections address specific aspects such as indoor swimming pool atmospheres, mechanical fasteners and combinations of stainless steel grades for fasteners.
Corrosion depends on more than the alloy
The publication also highlights several factors that can affect corrosion resistance in practical applications. These include welded or thermally cut components, extraneous rust, bimetallic corrosion, liquid metal-induced stress corrosion cracking and the influence of rain washing. Further guidance covers the welding of high-carbon grades and sulphur-alloyed grades intended for improved machinability.
The expanded scope reflects the large variety of stainless steels available to designers and plant operators. EN 10088-1 alone specifies the compositions of more than 180 stainless steel grades listed in European standards. Selecting an appropriate grade therefore requires consideration of the complete application profile rather than an isolated material property.
