Heat Exchangers

BÖHLER A959 (Alloy 28, UNS N08028, W. Nr. 1.4563) is a nickel-iron-chromium alloy with additions of molybdenum and copper. It has excellent resistance to both reducing and oxidizing acids, to stress-corrosion cracking, and to localized attack such as pitting and crevice corrosion. The alloy is especially resistant to sulphuric and phosphoric acid. Equipment used for chemical processing, pollution control equipment, oil and gas well piping ,natural gas and oil transportation, nuclear fuel reprocessing and transportation, acid production and pickling equipment and transportation The alloy was originally developed for use in the manufacture of phosphoric acid, especially for heat exchangers in the concentration unit, where corrosive conditions are at their worst.

BÖHLER A965SA is an austenitic stainless steel alloy with 6% molybdenum and nitrogen. It has very high resistance to crevice and surface corrosion and was specially developed for the requirements of the chemical industry, the pulp and paper industry and the oil/gas industry. Due to its PREN value of over 40, the material is particularly resistant to seawater and is therefore often used in offshore technology. Furthermore, BÖHLER A965SA is resistant to intergranular corrosion up to 400°C. The required surface finish is pickled, scale-free heat treated or machined. For applications in highly corrosive environments due to chemically aggressive media, e.g. for equipment and installations cooled with seawater and parts for offshore installations. In the chemical industry, where resistance to attack by pure acids as well as chloride ion-containing acids (especially sulphuric acid), organic acids and mixed acids in the higher pressure and temperature range is required. The increased resistance to crevice corrosion also allows the use where incrustations must be expected and / or where the formation of crevices cannot be avoided by constructive measures.

BÖHLER H500RB (Alloy 800, 800HT) is an austenitic, high-temperature iron-nickel-chromium alloy with good creep rupture strength at temperatures above 600°C. This material also has good resistance in oxidising, carburising and sticking atmospheres with good workability.  With a nickel content of more than 30%, this material has little tendency to precipitate sigma phase. In addition to the good mechanical long-term properties, BÖHLER H500RB is resistant to oxidation and carburisation up to approx. 1000°C. In certain temperature ranges, it shows resistance to sulphurous media. The original Alloy 800 is increasingly being replaced in the market by the variants 800H and HT. These can be solution annealed and therefore have improved creep rupture properties at high temperatures. The material BÖHLER H500RB fulfils the properties of Alloy 800 as well as Alloy 800H and 800HT by controlled contents of carbon, aluminium, titanium, silicon and manganese as well as controlled sum content of Al + Ti. In the case of Alloy 800H and HT, special solution annealing significantly increases the creep rupture strength at temperatures above 600°C.

BÖHLER L004 belongs to the group of highly corrosion-resistant nickel-chromium-molybdenum alloys with very low carbon, iron and silicon content and has good corrosion resistance, even at elevated temperatures. The combination of chromium with a high molybdenum content gives BÖHLER L004 exceptional resistance to a wide range of chemical media: e.g. contaminated, reducing mineral acids and good resistance under reducing and oxidizing conditions, e.g. hot, contaminated media such as sulphuric acid, nitric acid, dry chlorine, formic acid, acetic acid, solvents, chlorine and chloride-containing media. BÖHLER L004 exhibits a significantly reduced tendency to form precipitates in the temperature range between 650 and 1,040 °C due to the alloy composition. This improves resistance to intergranular corrosion. Due to the high nickel content, the material is practically insensitive to chloride-induced stress corrosion cracking even in hot chloride solutions. Due to its excellent thermal stability, the alloy can be welded without any problems and is generally used in the welded condition. Suitable for pressure vessels with wall temperatures from-196°C to 400°C.

BÖHLER L022 belongs to the group of highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloys with extremely low carbon and silicon contents. Good resistance to wet media, e.g. sulphuric acid, nitric acid, acid mixtures of sulphuric acid and oxidising acids with chloride ions. Recommended for use in the presence of strong oxidising agents such as iron(III) and copper(II) chlorides, chlorine gas, formic acid, acetic acid, seawater and other salt solutions. High resistance to crevice, pitting and stress corrosion cracking at elevated temperatures under oxidising and reducing conditions. Used in environmental engineering, e.g. in agitators, heat exchangers and spray systems in flue gas cleaning plants and in waste water treatment plants, evaporation plants in chemical process engineering, in chlorine bleaching plants and plants for the production of chlorine gas and hydrogen chloride, e.g. butterfly valves, gate valves, pipelines and centrifuges. Suitable for pressurised containers with wall temperatures from-196°C to 400°C. Due to its good thermal stability, BÖHLER L022 can generally be used in the welded condition without subsequent heat treatment.

BÖHLER L059 (2.4605/N06059) is a nickel-chromium-molybdenum material with high mechanical strength and excellent corrosion resistance. Due to its particularly low carbon and silicon content, the material does not tend to form precipitates at grain boundaries during welding or hot forming. BÖHLER L059 offers excellent corrosion resistance, both under oxidizing and reducing conditions, high resistance to chloride-induced pitting and crevice corrosion as well as insensitivity to stress corrosion cracking and resistance to mineral acids, especially sulphuric/hydrochloric acid mixtures. The alloy is therefore suitable for a wide range of applications in the chemical, petrochemical, energy and environmental technology sectors in chloride-containing media, in particular plant components in the pharmaceutical industry and also agitators for flue gas desulphurization plants (FGD) in fossil-fired power plants and waste incineration plants, components for seawater and concentrated brines, equipment and components for geothermal and sour gas applications, reactors for acetic acid and acetic anhydride as well as hydrofluoric acid and sulphuric acid coolers.

BÖHLER L276 is a nickel-chromium-molybdenum alloy with universal corrosion resistance unmatched by any other alloy. It has outstanding resistance to a wide variety of chemical process environments including ferric and cupric chlorides, hot contaminated mineral acids, solvents, chlorine and chlorine contaminated (both organic and inorganic), dry chlorine, formic and acetic acids, acetic anhydride, sea water and brine solutions and hypochlorite and chlorine dioxide solutions. BÖHLER L276 also resists formation of grain boundary precipitates in the weld heat affected zone making it useful for most chemical processes in the as-welded condition. BÖHLER L276 has excellent resistance to pitting and stress corrosion cracking. Some typical applications of BÖHLER L276 include equipment components in chemical and petrochemical organic chloride processes and processes utilizing halide or acid catalysts. Other industry applications are pulp and paper (digesters and bleach areas), scrubbers and ducting for flue gas desulfurization, pharmaceutical and food processing equipment.

BÖHLERL718 API (UNS N07718) is a high-strength, corrosion-resistant nickel-chromium-iron-molybdenum material with excellent corrosion resistance, especially in H2S and CO2 environments. The alloy is age-hardenable due to the addition of niobium, titanium and aluminium. BÖHLER L718 API is recognised by the oil industry for its simple and cost-effective production in combination with good tensile, fatigue, creep and fracture strength and is used in a wide range of applications in this sector. BÖHLER L718 API has excellent weldability and is resistant to cracking after welding. The material can be used at high temperatures. BÖHLER L718 API is available in the NACE/API 6A CRA versions with a minimum yield strength of 120/140 ksi and also in the high-strength version with 150 ksi. All hardness grades are suitable for sour service and can be used for pressurising and pressure-controlling equipment in corrosive environments. Typical applications include packers, pumps, connectors and fasteners as well as gate valves, throttle spindles, pipework hangers and fire safe valves, but also a wide range of downhole and completion components, nuclear and surface applications.