K3-en / PhotoRight


PHOTO OF THE MONTH


Every month we publish an interesting clip of corrosion in everyday life. We would like to point out that the process of metal corrosion takes place all around us and we cannot prevent it except in rare cases. Prevention or mitigation of the corrosion process requires actions, so strategies are needed to extend the life cycle of metals with contemporary corrosion protections.

You are kindly invited to submit a photo of the observed corrosion. We are accepting your submissions via this form.

February, 2024
Vasa Ship, Stockholm, Sweden
Vasa Ship, Stockholm, Sweden (P. Rodič) Vasa is a Swedish warship built between 1626 and 1628. The ship sank after sailing roughly 1,300 m into her maiden voyage on 10 August 1628. She fell into obscurity until she was located again in the late 1950s. The ship was salvaged with a largely intact hull in 1961 and in 1988 was permanently transfered to The Vasa museum. The ship was built on the orders of the King of Sweden Gustavus Adolphus as part of the military expansion he initiated in a war with Poland-Lithuania (1621–1629). She was constructed at the navy yard in Stockholm and armed primarily with bronze casted cannons. It was richly decorated and upon completion was one of the most powerfully armed vessels in the world. However, Vasa was dangerously unstable, with too much weight in the upper structure of the hull. Despite that, she was ordered to sea and foundered only a few minutes after encountering a wind stronger than a breeze. During the 1961 recovery, thousands of artifacts and the remains of at least 15 people were found in and around Vasa's hull by marine archaeologists. Among the many items found were clothing, weapons, cannons, tools, coins, cutlery, food, drink and six of the ten sails. The artifacts and the ship herself is giving us invaluable insights into details of naval warfare, shipbuilding techniques and everyday life in early 17th-century Sweden. Today Vasa is the world's best-preserved 17th century ship. The wreck of Vasa continually undergoes monitoring and further research on how to preserve her. Ship sinks in 32 m of water in the stocholm shipping channel. Over the years, Vasa settles in mud and clay. The iron bolts that hold the hull together and the cannonballs on board rust. As a result, iron penetrates the wood. Hydrogen sulfide also penetrates the wood. Waste dumped directly in to the harbour water, during rotting, it produces hydrogen sulphide and consumes the oxygen in the water. This polluted water, low in oxygen, helps preserve the ship. It is difficult for wood-attacking fungi and bacteria to survive. They managed to destroy only few mm of the wood surface. Almost all the objects of wrought iron corroded away while ship was under water. Most of the cast iron objects survived and could be conserved, although they have rusted. Cast iron has a grater carbon content than wrought iron. Even if all the iron corrodes, the carbon structure preserves the object's shape. Vasa's iron was conservated by heating to hight temperatures in hydrogen gas, which converts the corrosion back to metal. The surfaces were then sealed with paraffin wax to prevent new corrosion.

January, 2024
Lokomotive series 62
Lokomotive series 62, Vrhnika, Slovenia (P. Rodič) Locomotive 62-121 has represented the locomotives of its series at the Railway Museum of Slovenian Railways for many years. From October 6, 2023, it is in a new location at the former terminus in Vrhnika. It was built in 1957, is 9 m long, weighs 48 tons, and reached a top speed of 45 km/h. More information is available here.

December, 2023
Genetically Modified Little Mermaid, Bjørn Nørgaard, Langelinie Pier, Copenhagen, Denmark
Genetically Modified Little Mermaid, Bjørn Nørgaard, Langelinie Pier, Copenhagen, Denmark (M. Dlouhy) Crafted by Danish Professor Bjørn Nørgaard from the Royal Danish Academy of Fine Arts in 2006, the bronze "Genetically Modified Little Mermaid" offers a postmodernist interpretation. Unlike its original predecessor by Edvard Eriksen, this rendition showcases a distorted physique—elongated limbs, a hunched posture, and a face lacking distinct features. Part of Nørgaard's "Genetically Altered Paradise," this statue challenges genetic conventions, presenting a whimsical spin on Eriksen's original creation. Nearby, one can find abstract sculptures of Adam, Mary Magdalene, a pregnant man, and Jesus Christ, forming an intriguing cluster of artistic expressions. The statue has not yet been vandalized to this day, maybe this is also the reason why it is not as well preserved as the original.

November, 2023
Little Mermaid, Edvard Eriksen, Langelinie Pier, Copenhagen, Denmark
Little Mermaid, Edvard Eriksen, Langelinie Pier, Copenhagen, Denmark (M. Dlouhy) Unveiled in 1913, The Little Mermaid, a gift from brewer Carl Jacobsen to Copenhagen, rests at Langelinie Pier in bronze. The statue is 1.25 metres tall and weighs 175 kilograms. Inspired by Hans Christian Andersen's allegorical tale of a sacrifice for a forbidden love, mermaid gazes towards the shore, longing for her prince, surfacing at dawn and dusk. Jacobsen's fascination sparked from a ballet performance, leading him to commission sculptor Edvard Eriksen for the artwork. The sculpture's inspiration came from ballerina Ellen Price, who played the lead in the 1909 ballet. However, as Price declined to pose nude, Eriksen's wife became the model. Despite enduring vandalism, losing her head twice and an arm once, and enduring paint attacks, The Little Mermaid is always restored, welcoming visitors to Copenhagen's harbor.

October, 2023
Monuments of Gothenburg, Gothenburg, Sweden
Monuments of Gothenburg, Gothenburg, Sweden (I. Milošev) The annual conference of The Electrochemical Society (ECS) held in October 2023 was after more than ten years organized again in Europe, in Gothenburg, Sweden. ECS conferences are mostly organized in the USA. Gothenburg is a beautiful city, the second largest in Sweden, founded in 1621 by King Gustav Adolf as a heavily fortified trading colony. Gothenburg has a strategic position at the mouth of the Göta River in the North Sea and is today an important port. Gothenburg is also a city of students, as two important universities are located here - Gothenburg University and Chalmers University of Technology. Volvo was founded in Gothenburg and has its headquarters here. There are many beautiful monuments in the city, which attract for their artistic value and placement in the urban space. The green patina of the bronze and copper monuments, created over decades, gives the city a special touch.

September, 2023
Granattor, Millstätter Alpe, Austria
Granattor, Millstätter Alpe, Austria (L. Gašparič) The iron passage on the mountaintop, with a height of 3.20 m and a width of 3.50 m, is filled with tons of garnet rocks. It is located in the region with the largest garnet deposits in the Alps, and its walls tell the story of the ruby-red precious stone.

August, 2023
Boat launching structure, Korčula, Croatia
Boat launching structure, Korčula, Croatia (B. Kapun) The iron structure for boat launching has been severely affected by corrosion. Salt-enriched seawater has caused rust. The presence of organisms such as algae and bacteria has further accelerated the corrosion. Instances like these from nature underscore the impact of natural factors on metallic structures in the marine environment and highlight the importance of using appropriately resistant materials and regular maintenance.

July, 2023
Turquoise Cannons at Citadel of Quitbay, Alexandria, Egypt
Turquoise Cannons at Citadel of Quitbay, Alexandria, Egypt (I. Milošev) The Citadel of Quitbay was built in the 15th century by Sultan Abu Al-Nasr Quitbay on Pharos Island in the Gulf of Alexandria, Egypt. The Lighthouse of Alexandria, one of the Seven Wonders of the Ancient World, once stood on this site, which was destroyed in an earthquake in the 10th century. The monumental fortress, surrounded by the sea, was one of the most important defensive fortresses in Egypt and along the Mediterranean coast. Over time, the citadel lost its military importance. In the 19th century, during the reign of Muhammad Ali Pasha, the citadel was renovated, and the most modern weapons of that time were placed inside the walls - cannons made of copper alloy, probably bronze, that is, an alloy of copper and tin. At the time, copper cannons were more prized than iron cannons because they were lighter, could withstand the stress of firing better, and were more corrosion-resistant. Due to the long-term, almost 200-year exposure to the sea atmosphere, a beautiful turquoise patina has formed on the surface of the bronze. The colors of patinas, which spontaneously form over time on metal surfaces, thus depend on the chemical composition and humidity of the atmosphere to which they are exposed. The green patina on bronze may consist of a mixture of copper chlorides, sulfides, sulfates, and carbonates. The turquoise color is created in the presence of sea salts and ammonia.

June, 2023
Self-Portrait in a Cap and Scarf with the Face Dark, Rembrandt, 1633, National Gallery of Slovenia, Ljubljana, Slovenia
Self-Portrait in a Cap and Scarf with the Face Dark, Rembrandt, 1633, National Gallery of Slovenia, Ljubljana, Slovenia (A. Kraš) In the context of metal etching, corrosion assumes a deliberate and controlled role. Etching selectively removes the surface of a material using corrosive substances. By protecting the desired parts of the surface from corrosion, only the unprotected areas are removed to create specific patterns. It finds applications in art, printing, and industry. Rembrandt van Rijn, the legendary Dutch painter, printmaker and draughtsman, employed this technique with extraordinary finesse. While the tools, materials, and techniques have expanded significantly since Rembrandt's time, the fundamental principles of etching in art remained the same. Rembrandt's etching begins with coating the metal plate (usually copper) with an acid-resistant substance called the "ground." During Rembrandt's time, the ground was made from powdered bone ash or charcoal and linseed oil The ground acts as a barrier, preventing the acid from affecting areas that should remain untouched. Once the ground is applied, Rembrandt used a needle-like tool called an "etching needle" or a brush to meticulously scratch through the ground, exposing the underlying metal. Subsequently, the metal was immersed in an acid bath typically made of nitric acid, which selectively corroded, i.e. dissolvde the exposed metal. The duration of immersion determined the depth of corrosion and the intensity of the resulting etched lines or textures. This process required precision and control, as Rembrandt had to etch each line with varying pressure to achieve a range of light and shadow effects. After the ground was cleaned, the plate was positioned on the bed of a rolling printing press and covered with a sheet of paper onto which the etching pattern was finally printed. In addition to the ability to produce multiple prints from a single metal plate, existing etchings could be modified by grinding specific parts of the plates and reetching, allowing for changes in the prints. In his self-portrait shown in the picture, Rembrandt's deft etching skills can be observed through the intricate lines that delicately define his face and the folds of his clothing.

May, 2023
100 years of corrosion under ground, Godovič, Slovenia
100 years of corrosion under ground, Godovič, Slovenia (T. Poženel Kovačič) Unfinished railway tunnel close to Godovič was being built in 1916 – 1917, time of the 1st world war. 28 km long railway line between Logatec and Črni Vrh was built by Russian prisoners under Austro-Hungarian captivity. This normal railway line should replace narrow rail which already worked for the aim of supplying the Isonzo battlefield. After the Italian army was defeated in October 1917, Austro-Hungarians stopped the construction immediately. An unfinished 400 m-long tunnel is a technical example of how railway tunnels were built at the beginning of the 20th century. The tunnel stayed unfinished but part of it was later rearranged by the Italian border army into the bunker which was part of the Rapall border line. In 1920 western third of today's Slovenian territory together with Croatian Istria and the city Reka stayed under the control of the Kingdom of Italy. So it remained till 1947. The photo shows the surface of the steel load-bearing element and ceiling after more than 100 years at constant temperature and increased humidity which are typical for cave environments. On exposed surfaces are visible thick layers of iron oxides (Fe2O3·xH2O), a part of the surface is plaster-protected. Water penetrates through the ceiling and therefore also limestone depositions in the form of stalactites are visible.

April, 2023
Washington Monument, Washington D.C., ZDA
Washington Monument, Washington D.C., ZDA (I. Milošev) Washington Monument in Washington D.C. honors George Washington, the first president of the United States. The hollow, Egyptian-style obelisk, 170 m high, was completed in 1888 and is made of marble, granite, and bluestone gneiss. It was the world's tallest structure between 1884 and 1889, after which the Eiffel Tower overtook it. The obelisk is topped with a pyramid made of solid aluminum with a weight of 2.85 kg. Aluminium was chosen because it is light and resistant to corrosion. In the 1880s, aluminum was expensive and a rare metal used primarily for jewelry. The aluminum pyramid was the largest aluminum casting of its time.

March, 2023
Tourmaline corrosion, Salzburg, Austria
Tourmaline corrosion, Salzburg, Austria (A. Kraš) Corrosion, in its broadest sense, is the gradual deterioration of a material as a result of its interaction with its surroundings. Corrosion is more than 90 % electrochemical in nature and is most commonly associated with industrially manufactured metals, though it is also observed in other materials. The common denominator for corrosion of all materials is a local defect in materials, whether it is represented as the grain boundaries, outer or inner edges, mechanical damage, etc. The image depicts the corrosion of gemstones named tourmalines, the most complex silicate minerals composed primarily of aluminum and boron cyclosilicates. It is seen that the preferential dissolution i. e. corrosion, happens on crystal defects. Deep holes were formed in an otherwise perfectly preserved crystal.

February, 2023
Gold and silver ores, Salzburg, Austria
Gold and silver ores, Salzburg, Austria (A. Kraš) Due to a stable electron configuration, noble metals, including gold, silver, platinum, palladium, rhodium, ruthenium, and osmium, resist chemical reactions, including corrosion. This also reflects in resistance to various weathering processes, which is why noble metals are often found in their free elemental state in nature. In contrast, non-noble metals are typically found in the form of isolated pockets where natural chemical processes reduce their ores, leaving behind small flakes or inclusions of pure metal. Here we come to the exact origin of corrosion process, as a natural tendency of a refined metal to return to its original, thermodynamically stable state of ore. The main corrosion products are thus compounds found in ores, particularly oxides and hydroxides, occasionally accompanied with chlorides or sulphates.

January, 2023
Corrosion on the exterior of cans, Ljubljana, Slovenia
Corrosion on the exterior of cans, Ljubljana, Slovenia (S. Stavber and A. Kraš) Many reactive (aggressive) organic compounds are stored in double packaging and usually refrigerated or even frozen. The inner packaging is made of a specific material, while the outer packaging is usually made of metal cans for transportation and safer storage until use. The interior of the cans is often coated with materials that protect against corrosion, and the space between the inner and outer packaging is filled with non-flammable and chemically stable material. This protection is sufficient for safe transportation and short-term storage of aggressive chemicals. However, the exterior surface of the protective cans is still exposed to an aggressive corrosive atmosphere that is always present in chemical storage areas. After prolonged and inappropriate storage of such chemicals, significant corrosion of the packaging (see picture) and surfaces of the storage area (e.g. refrigerators) occurs. Therefore, the advice is to use aggressive chemicals as soon as possible and dispose of unused ones. Another option is to purchase extremely expensive, specialized, and adapted refrigeration equipment.

December, 2022
Anodic (left) and cathodic (right) protection, Vrhnika, Slovenia
Anodic (left) and cathodic (right) protection, Vrhnika, Slovenia (P. Rodič) [LEFT] The metal construction of city lights is exposed to various external conditions (e.g., cold weather, snow, and moisture), so adequate corrosion protection is needed. One of the protection methods is with a zinc strip, which is fixed on the lower part of the metal construction and buried in the ground. This provides long-lasting corrosion protection. [RIGHT] The cathodic protection measuring point is often observed in nature (yellow concrete sign). But the most interesting part is hidden under it, as it indicates where underground pipelines (e.g. natural gas) are. They are connected with cathodic protection, which enables durable corrosion protection of metal pipes.

November, 2022
Diatoms on the coating surface, Adriatic sea, Slovenia
Diatoms on the coating surface, Adriatic sea, Slovenia (B. Kapun and I. Milošev) Biofouling is a layer of micro/macro organisms formed on artificial or natural surfaces such as ships and piers upon immersion in aquatic, mainly marine environments. The biofouling process starts within a few minutes after immersion due to physical interactions between the surface and organic molecules (proteins). This conditioning film is the starting point for further attachment and growth of micro- and macrofouling. We conducted field testing of sol-gel coated Al-Si alloys in the Adriatic Sea to test their resistance against corrosion and biofouling. Electron microscopy image shows diatoms formed at the coating surface after 1 month of immersion. A diatom (diatoma) is a group of microalgae. Diatoms may have different shapes, but most are broadly bilaterally symmetric, as in the photo. Diatoms are surrounded by a cell wall made of transparent, opaline silica SiO2, usually ornamented by different patterns. Like plants, diatoms convert light energy to chemical energy through photosynthesis and generate 20-30 % of the air we breathe.

October, 2022
Tramway tracks on the road, Berlin, Germany
Tramway tracks on the road, Berlin, Germany (A. Kraš) Due to the lower construction costs associated with the use of tram/railway tracks to carry back electricity, complete isolation of the rail metal surface as a means of corrosion protection is less feasible. Corrosion pits on railways tend to form rapidly and fortunately, merge quickly on the large surface rather than growing deeply. This results in general corrosion, where material loss, unlike localized attacks, does not pose a threat to construction integrity. Rust formed by general corrosion provides a certain degree of corrosion protection after some time, which, when combined with proper maintenance and inspection, can ensure safe railway operation for many years, if not decades.

September, 2022
A ships' bow, Nerezine, Croatia
A ships' bow, Nerezine, Croatia (A. Kokalj) The remains of a ship on which large stones were placed in order to sink it and make a pier out of it. Only the bow protrudes from the water, which is already quite corroded.

August, 2022
Copper and brass in everyday life, Ljubljana, Slovenia
Copper and brass in everyday life, Ljubljana, Slovenia (I. Milošev) Drinking coffee brewed in a džezva (coffee pot) and served in a fildžan cup with a cube of sugar and ratluk (Turkish delight) is a special experience. Coppersmithing - the tradition of making these objects from copper or brass - goes back centuries in Bosnia.

July, 2022
Summertime, Red sea, Egypt
Summertime, Red sea, Egypt (I. Milošev) Ships need efficient corrosion protection in seawater in the form of paints and coatings, especially those more exposed parts.

June, 2022
Richard Serra: Installation in Guggenheim Museum Bilbao, Spain
Richard Serra: Installation in Guggenheim Museum Bilbao, Spain (M. Dlouhy) Richard Serra is an artist of sculptural minimalism. His works of art are enormous round metallic configurations like one represented in the picture. The weathering steel he uses is frequently referred to as COR-TEN. Material of this type is resistant to atmospheric corrosion because of its chemical composition. When exposed to a real environment, it forms a protective oxide layer, creating the look of a "weathered" surface while protecting the surface from further damage. With the passage of time, such steel develops a rust-like appearance.

May, 2022
Galvanization of steel, Ljubljana
Galvanization of steel, Ljubljana (A. Kraš) During galvanization, as molten zinc cools down, snowflake-like or six-fold star patterned crystal grains, named „spangles“, develop on the surface of steel. It is believed that lead presence as impurity in zinc ore causes spangling and as such, spangles served as an indicator of steel protection in history. However, with today's zinc refining processes, lead is removed, and spangle-free galvanized steel surfaces can also be obtained.

April, 2022
Underwater Corrosion, Sharm el Sheikh, Egypt
Underwater Corrosion, Sharm el Sheikh, Egypt (G. Milošev) The wreck of the Thilstegrom is one of the most famous diving sites in the world. It is located in the Sharm el Sheikh area of Egypt at the depth of 30 m. Thilstegron was a British cargo ship bombed by the German army in 1941 in the Red Sea. The photo was taken in 2019 by Goran Milošev, and the diver is Ingrid Milošev.

March, 2022
Stairs Fence, Koper
Stairs Fence, Koper (B. Kapun) A special form of corrosion called galvanic corrosion often occurs at the junction of two metals. Galvanic corrosion occurs when two dissimilar metals are immersed in a conductive solution and are electrically connected. One metal (the cathode) is protected, whilst the other (the anode) is corroded. .

February, 2022
Remains of the railway bridge, Kranjska Gora
Remains of the railway bridge, Kranjska Gora (N. Lešić) The Jesenice-Trbiž railway line was completed and opened in 1870, and it was taken out of service in 1966 due to the dilapidated infrastructure. The picture shows an iron construction of the bridge, which is well eaten away by rust due to a lack of protection. The term rust refers to surface oxidative damage to iron, where various amorphous reddish-brown iron (III) oxide hydrates are formed.

January, 2022
Roofs in Paris,  Paris, France
Roofs in Paris, Paris, France (I. Milošev) Paris is famous for its grey zinc roofs. By decree of Napoleon III, zinc began to be used in the mid-19th century, as it was available in Moresnet mines. The renovation of Parisian roofs was entrusted to Baron Hausmann, who, with the introduction of characteristic elongated windows and zinc roofs, completely transformed the appearance of the city, which to this day remains one of Paris’ greatest attractions. The protective matt patina on zinc protects the roofs from weathering. The production and installation of welded zinc roofs are extremely demanding and the know-how of the Paris roofers is placed under the protection of UNESCO World Heritage since 2019.

December, 2021
Lost shopping cart,  Kotor, Montenegro
Lost shopping cart, Kotor, Montenegro (M. Poberžnik) In environments with many microorganisms, microbes can form biofilms on the surface of a wide range of materials. Within biofilms, a microenvironment conducive to corrosion processes can be established. This type of corrosion is called microbial corrosion or biocorrosion.

November, 2021
Weathering steel,  Štanjel
Weathering steel, Štanjel (I. Milošev) The stairs at the viewpoint in Štanjel Castle are made of so-called weathering steel. It is a family of low-carbon structural steels, we call it also, corten (COR-TEN), which contain small amounts of copper, chromium, nickel, phosphorus, silicon and manganese. Upon air exposure, a protective layer that is resistant to weathering is formed on the surface and the structure, therefore, does not require painting. So it is not about harmful rust but protective patina. Earthy colours of these protective layers of rusty patina are liked by some, not by others.

October, 2021
World War I military trench, Sabotin
World War I military trench, Sabotin (L. Gašparič) Sabotin is a 609-meter high hill above Nova Gorica. For the purposes of the First World War, the land was heavily excavated. The summit was an important defensive point that defended Gorizia until August 6, 1916, when after a short and bloody battle, the mountain was captured by the Italians. The post-war degrading iron remnants due to corrosion still remind us of the horrors of war from more than 100 years ago.

September, 2021
Haizearen orrazia, San Sebastian
Haizearen orrazia, San Sebastian (M. Dlouhy) Haizearen orrazia, is from the Basque literally translated into The Comb of the Wind. It is a collection of three iron sculptures by Eduard Chillid. The Basque Country is particularly well known for its metal industry, especially iron ore mining and steel production, which are still among the predominant industries in northern Spain.

August, 2021
Galvanic corrosion on top of Rašica, Rašica
Galvanic corrosion on top of Rašica, Rašica (A. Kraš) On top of Vrh Staneta Kosca, which is better known under the name Rašica hill, stands a 17 meters high Kamnik Battalion memorial tower placed there in 1957. The tower, that has been already affected by the galvanic corrosion, offers a splendid view of the surrounding hills and mountains, especially the Kamnik-Savinja Alps as well as the entire Ljubljana basin.

July, 2021
Upper Funicular Railway Station, Ljubljana castle
Upper Funicular Railway Station, Ljubljana castle (I. Spajić) More than a century-old idea of a funicular railway to Ljubljana Castle was realized in 2006 and has carried more than 4.5 million passengers to date.

June, 2021
View at the train station, Ljubljana
View at the train station, Ljubljana (L. Gašparič) On June 2, Slovenia celebrates the Railwaymen's Day. On this day in 1846, the first train arrived on the Slovenian territory. On this occasion, we are dedicating this month's photo the railway industry.

May, 2021
Uvala Luka, Rakalj, Istra
Uvala Luka, Rakalj, Istra (I. Milošev) A ship from the Second World War adds a special atmosphere to the beautiful bay Luka. Years in seawater have left inevitable consequences on the metal structure.