Maraging steel

About: Maraging steel is a research topic. Over the lifetime, 1728 publications have been published within this topic receiving 19886 citations. The topic is also known as: martensitic ageing steel.

Sintering of maraging steel with phosphorous additions

Abstract: The aim Of this study was to develop a steel powder system for rapid tooling applications. The properties required are rapid densification, dimensional precision. high mechanical strength and corrosion resistance. To this end. the densification and microstructural development of a loose packed 200 grade maraging steel powder sintered with ferrophosphorous additions was examined. Liquid initially formed from a reaction of the Fe3P and carbon, which was a residue of the polymeric binder used to shape the powder compact. This liquid caused a burst of sintering which ceased as the liquid dissipated. On further heating, a phosphorous rich supersolidus liquid appeared at triple points and grain boundaries leading to rapid densification and a sintered density of 98%.

Dynamic deformation and fragmentation response of maraging steel linear cellular alloy

Abstract: The dynamic deformation and fragmentation response of 25% dense 9-cell linear cellular alloy (LCA) made of unaged 250 maraging steel, fabricated using a direct reduction and extrusion technique, is investigated. Explicit finite element simulations were implemented using AUTODYN finite element code. The maraging steel properties were defined using a Johnson-Cook strength model with previously validated parameters. Rod-on-anvil impact tests were performed using the 7.6mm helium gas gun and the transient deformation and fragmentation response was recorded with highspeed imaging. Analysis of observed deformation states of specimens and finite element simulations reveal that in the case of the 9-cell LCA, dissipation of stress and strain occurs along the interior cell wells resulting in significant and ubiquitous buckling prior to confined fragmentation.

Additive manufacturing of corrosion-resistant maraging steel M789 by directed energy deposition

Abstract: Conventional maraging steels feature a combination of high strength and toughness, but they often suffer from low corrosion resistance. Hence, maraging steel M789 was developed to alleviate this issue while maintaining its strength. Most studies of maraging steels processed by additive manufacturing (AM) focus on utilizing laser powder bed fusion (LPBF). However, the research in laser-directed energy deposition (L-DED) fabrication of corrosion-resistant maraging steels is limited. The different cooling rates experienced by materials during L-DED and LPBF processing give rise to differing microstructures and mechanical properties. In this study, the L-DED process was adopted to manufacture nearly-fully dense M789 parts, which were subsequently subjected to direct aging and solutionizing + aging heat treatments. Electron backscatter diffraction (EBSD) analysis reveals a martensitic structure in both as-fabricated and heat-treated samples with the presence of austenite in the as-fabricated and directly aged samples. Scanning transmission electron microscopy (STEM) and transmission Kikuchi diffraction (TKD) reveal the presence of Ti- and Al-rich precipitates within the martensites after the solution and aging treatment, suggesting that Orowan looping around precipitates, grain boundary strengthening, and solid solution strengthening are responsible for the high yield strength of L-DED M789. Besides, the as-fabricated alloy shows higher pitting potential than solutioned and aged sample. This work serves as a guidance for the fabrication of corrosion-resistant maraging steels by L-DED and accelerate the implementation of maraging steels for marine and offshore applications.

Neutron and gamma-ray shielding properties of modified Ni- Ti- X Mo maraging steels

Abstract: MCNP5 program was used to investigate the neutron and gamma shielding properties of Ni-Ti- X Mo maraging steels. The MCNP5 program experimental setup was designed using neutrons of 14.1 MeV from sealed neutron tube and 60Co as a gamma ray source. Particular attention was given to the shielding properties of neutron and gamma for low nickel free cobalt, titanium containing modified maraging steel in correlation to the molybdenum as alloying element. Based on the shielding properties, Ni-Ti- X Mo maraging steels with different molybdenum content show the same shielding properties of neutron and gamma rays when compared to the standard maraging steel 18Ni (C250). In addition, the secondary gamma ray spectra due to neutron irradiation show no obvious difference between all steels under investigation. A comparison with available calculated and experimental results of the mass attenuation coefficient at gamma energies 1173 and 1332 keV for other steels has been done. From an economic point of view newly cobalt free low-nickel maraging steel is cheaper than standard C250 maraging steel as shielding materials. Key words: Neutron shielding, gamma ray shielding, maraging steel, MCNP5 program.

Beryllium-containing maraging steel

Abstract: A steel which is age-hardenable in the martensitic state has the following weight percentage composition:- The steel may be cast, homogenized at 1150 DEG -1260 DEG C., hot-worked(and, if desired, cold-worked) to the required shape, solution-treated at 760 DEG -1095 DEG C., refrigerated at -73 DEG C. or lower and/or cold-worked, and aged at 425 DEG -540 DEG C. It may be used in the manufacture of fasteners, e.g. bolts, pressure vessels, wrenches, tools, machine parts, and bearing components.