Shafts for Mechanical Engineering

BÖHLER A903 (UNS S32205) is the most common stainless ferritic-austenitic Cr-Ni-Mo steel with nitrogen addition. In addition to good strength properties, this steel offers high corrosion resistance, especially against stress corrosion cracking in chloride-containing solutions, and is resistant to intergranular corrosion up to 300°C. The alloy should not be used at temperatures above 300°C due to embrittlement. Heat treatment after welding is not necessary. Required surface finish: pickled, scale-free heat treated or machined. Commonly used in the oil and gas industry, hydroelectric power, pressure vessels, pulp and paper industry, components and chemical tanks, such as parts for separators and heat exchangers and parts in the paper industry, oil and gas extraction , compressors, seawater desalination.

BÖHLER A962RC (Alloy 904L, UNS N08904) is a super-austenitic stainless steel designed for a medium to high level of corrosion resistance. The alloy contains high levels of chromium and nickel with additions of molybdenum and copper to provide higher corrosion resistance in certain media. The alloy is produced to low carbon levels for use in the welded condition as in welded vessels and other large and complex fabrications. No post-weld heat treatment required. The high nickel (25%) and molybdenum (4.5%) contents of BÖHLER A962RC provide good resistance to chloride stress corrosion cracking. The Chromium, molybdenum and nickel levels provide general corrosion restistance and restistance to chloride pitting corrosion above the level of Types 316 and 317 in many media. The copper addition provides added resistance to reducing media such as hot phosphoric acid and dilute sulfuric acid.

Böhler A970 is a stainless austenitic CrNiMoCu steel with excellent resistance to pitting, crevice and stress corrosion cracking. It is also resistant to intergranular corrosion up to 400°C. Required surface finish pickled, scale-free heat treated or machined. For components subjected to highly corrosive conditions, e.g. in seawater-cooled plants and in offshore applications. In areas of the chemical industry where, at higher pressures and temperatures, there is exposure to pure acids as well as acids containing chlorine ions (especially sulphuric acid), organic acids and acid mixtures. Due to the increased resistance to crevice corrosion, it can also be used wherever the formation of deposits is to be expected or where crevices cannot be prevented by constructive measures.

BÖHLER N404 is a stainless, soft martensitic Cr steel with 5% nickel and molybdenum addition with higher corrosion resistance than that of stainless steels of type 1.4313. The molybdenum addition also permits limited use in the maritime sector. BÖHLER N404 is particularly insensitive to intergranular corrosion and very resistant to fatigue and stress corrosion cracking and offers good mechanical properties in the quenched and tempered condition. This makes this material very suitable for use in the oil and gas sector, e.g. for fittings, pumps, compressors, centrifuges, hydropower machinery, reactor technology, shipbuilding, chemicals, petroleum technology, aviation and refrigeration technology. Very good low-temperature properties. Recommended application temperature from – 60 to 350°C. Special heat treatment to max. 23 HRC is required for sour gas stress in petroleum technology. In order to achieve the best possible corrosion resistance, the relevant surfaces must be polished.

BÖHLER N685 is a corrosion-resistant steel with molybdenium and vanadium additions in the form of bars, wire, forgings, and forging stock. These products have been used typically for parts in engineering and medical applications requiring hardness up to 58 HRC and resistance to wear, corrosion, and oxidation, but usage is not limited to such applications.

BÖHLER N700 is a martensitic, corrosion-resistant, precipitation-hardenable chromium-nickel-copper steel with high strength and toughness. Further increases in strength can be achieved by cold forming and subsequent precipitation hardening. These products are typically used for parts that require higher corrosion resistance than the usual 13% or 17% chromium steels and high strength. Various remelting processes are used to improve steel purity and homogeneity. (ESR, PESR, VAR). Certain processing methods and operating conditions can make these products susceptible to stress corrosion cracking. For applications such as bolting where stress corrosion cracking is possible, the product should be aged for at least 4 hours at the highest temperature compatible with the strength requirements, but in no case lower than 552 °C. Typical engineering applications include surgical and dental instruments as well as aerospace components, reactor construction, highly stressed pump parts, springs and ship shafts.

BÖHLER N701 is a high quality, vacuum remelted, corrosion resistant steel for aerospace applications in the form of bars for machining up to 200 mm in diameter. It is a martensitic, precipitation hardenable chromium-nickel-copper steel with high strength and toughness. These products are typically used for parts that require corrosion resistance, high strength up to 600 °F, and exhibit good toughness & strength in the transverse direction of large dimensions. However, use is not limited to such applications. Certain processing methods and operating conditions can cause these products to become susceptible to Stress corrosion cracking.

BÖHLER N709 is a corrosion-resistant steel for engineering applications in the form of bars, wire, and forgings with diameters/thicknesses up to 65 mm in the solution-annealed condition, as well as pre-forging stock of any size. It is a martensitic, precipitation-hardenable chromium-nickel-molybdenum-aluminum steel with high strength and toughness. These products are typically used for parts requiring corrosion resistance, stress corrosion resistance, and high strength up to 316 °C, with good ductility and transverse strength at large cross-sectional dimensions. However, their use is not limited to such applications. Certain processing methods and operating conditions can make these products susceptible to stress corrosion cracking.

BÖHLER N765 (UNS S46500) is a double vacuum-melted, stainless, maraging steel (PH-Grade) with a unique combination of high strength, toughness and corrosion resistance. The products are typically used for heat-treated parts where resistance to stress corrosion cracking, high strength and toughness up to 427 °C (800 °F) with good ductility and transverse strength are required. BÖHLER N765 material achieves a tensile strength of over 250 ksi (1722 MPa) when aged at 950 °F (H950 condition) and offers a superior combination of strength, toughness and stress corrosion cracking resistance compared to other high strength PH-steels such as 15-5PH or PH 13-8Mo. Hardening temperatures from 950°F to 1050°F can be selected to achieve the desired combination of strength, toughness and stress corrosion cracking resistance. The alloy not only meets the special and demanding requirements of the aerospace industry, but is also used in marine equipment, firearms, hand tools, oil and gas drilling and the medical industry, among others.

“This specification covers a corrosion and heat resistant steel in the form of bars, wire, forgings and forging stock. It is an austenitic, precipitation hardenable, iron-nickel-chromium-molydenum-titanium steel of ESR quality. Alloying elements of aluminium and titanium allow this material to undergo precipitation hardening (ageing) through the formation of intermetallic phases. The addition of molybdenum increases the mechanical properties and resistance to creep at high temperatures. These products have been typically used for parts in power generation engineering i.e. gas turbines requiring moderate strength up to 704 °C (1300 °F) and oxidation resistance up to 816 °C (1500 °F), but their use is not limited to such applications.”

Components featuring elevated high-temperature strength for use in thermal engines and power plants, such as turbine blades, turbine discs, screws, bolts, pins and shafts.