Oțelurile cu 10 până la 17% crom, conținut scăzut de carbon și proporții de nichel au ca rezultat o microstructură de martensită dură și ating rezistențe de până la 1700 MPa prin aliere cu cupru sau aluminiu cu un tratament simplu de întărire cu schimbare dimensională redusă. Domeniile preferate de aplicare în condiții de stres coroziv sunt aviația, industria petrolului și a gazelor și tehnologia de măsurare și control.
Acest subgrup special de oțeluri inoxidabile martensitice, oțelurile inoxidabile martensitice moi și întărite prin îmbătrânire (supermartensite) obțin microstructura martensitică prin conținuturi mai mari de Ni cu conținuturi simultan scăzute de C și N. Acest lucru este asociat cu o tenacitate mai mare, o sudabilitate mai bună și, datorită legăturii mai reduse a Cr cu C, și cu o rezistență mai mare la coroziune. Elementele de aliere precum Cu, Ti și Al sunt utilizate pentru a obține sisteme de aliaje călibile (oțeluri PH) și pentru a crește rezistența prin precipitarea fazelor intermetalice din martensită în cursul unui tratament termic simplu, cu dimensiuni reduse.
Aplicațiile obișnuite pentru astfel de oțeluri sunt în ingineria mecanică, de exemplu, elemente de fixare, arbori, arcuri, angrenaje și construcții ușoare, de exemplu, în industria aerospațială.
BÖHLER N700 is a high-quality corrosion-resistant steel in aerospace quality, in the form of bars, wire and forgings with a diameter/thickness of up to 203 mm in the solution-annealed condition, as well as starting material of any size for forging purposes. It is a martensitic, 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 requiring corrosion resistance and high strength up to 316°C. However, their use is not limited to such applications. 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. For applications such as bolting where stress corrosion cracking is possible, the product should be aged for a minimum of 4 hours at the highest temperature compatible with the strength requirements, but in no case lower than 552°C.
Citește mai multBÖHLER 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.
Citește mai multBÖHLER N701 AMS is a premium, aerospace-quality corrosion-resistant steel available in bars, wire, and forgings with diameters/thicknesses up to 203 mm in the solution-annealed condition, as well as pre-forging stock of any size. It is a martensitic, precipitation-hardenable chromium-nickel-copper steel with high strength and toughness. Further strength increases can be achieved through cold working and subsequent precipitation hardening. These products are typically used for parts requiring corrosion resistance and high strength up to 316 °C and must exhibit good transverse toughness and strength in large 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.
Citește mai multBÖHLER N709 is a premium aircraft-quality corrosion-resistant steel in the form of bars, wire, forgings up to 12.0 inches (305 mm) in diameter or least distance between parallel sides in the solution heat treated condition as well as stock of any size for forging. It is a martensitic precipitation hardenable chromium-nickel-molydenum-aluminium steel possessing high strength and toughness. These products have been used typically for parts requiring corrosion resistance, stress-corrosion resistance and high strength up to 600 °F (316 °C) with good ductility and strength in the transverse direction in large section sizes but,but usage is not limited to such applications. Certain processing procedures and service conditions may cause these products to become subject to stress-corrosion cracking.
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