Showing papers on "Maraging steel published in 1996"
TL;DR: In this article, a new type of maraging steel with the composition 12Cr9Ni, 4Mo, 2Ni, and 2Cu (wt%) was developed by AB Sandvik Steel.
36 citations
TL;DR: In this article, changes in the lattice parameter of martensite phase in a maraging steel are measured as a function of ageing temperatures, which is attributed to depletion of alloying elements in the matrix as a consequence of precipitation and austenite formation.
Abstract: Changes in the lattice parameter of martensite phase in a maraging steel is measured as a function of ageing temperatures. A decrease in the lattice parameter is observed when aged between 400–650°C which is attributed to the depletion of alloying elements in the martensite matrix as a consequence of precipitation and austenite formation. An increase in the lattice from 650 to 710°C was characteristic of enrichment of alloying elements in the martensite matrix due to dissolution of austenite phase. A minimum value of the lattice parameter of martensite is observed at 650 °C which coincides with the maximum vol % of retained austenite. Electrical resistivity, hardness measurements, andin situ high temperature dilatometry was also carried out to delineate various precipitation reactions that occur in this steel.[/p]
34 citations
TL;DR: In this paper, the behavior of maraging steel used in the tanks of French plants for reprocessing radioactive water which may contain chloride ions at pH 3 was investigated, and the anodic and cathodic areas of steel corroded by pitting were shown using the scanning reference electrode Technique.
28 citations
TL;DR: In this paper, the effects of retained austenite produced by thermal cycling on the mechanical properties of a precipitation-hardened 350-grade commercial maraging steel were examined and the presence of retained Austenite caused decreases in the yield strength and ultimate tensile strength and effected a significant increase in the tensile ductility.
Abstract: The effects of retained austenite produced by thermal cycling on the mechanical properties of a precipitation-hardened 350-grade commercial maraging steel were examined. The presence of retained austenite caused decreases in the yield strength (YS) and ultimate tensile strength (UTS) and effected a significant increase in the tensile ductility. Increased impact toughness was also produced by this treatment. The mechanical stability of retained austenite was evaluated by tension and impact tests at subambient temperatures. A deformation-induced transformation of the austenite was manifested as load drops on the load-elongation plots at subzero temperatures. This transformation imparts excellent low-temperature ductility to the material. A wide range of strength, ductility, and toughness can be obtained by subjecting the steel to thermal cycling before the precipitation-hardening treatment.
24 citations
15 Apr 1996-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the volume fraction of austenite and dislocation density in electron beam weld joints of a martensitic-austenitic age-hardenable stainless steel were investigated using neutron diffraction.
Abstract: The volume fraction of austenite and dislocation density in electron beam weld joints of a martensitic-austenitic age-hardenable CrNiMoTiAl stainless steel were investigated using neutron diffraction. Experiments were performed on a high-resolution diffractometer which resolved microstrains of the order of 10 −4 . The effect of post-weld heat treatment on austenite content and dislocation density was investigated. As in other maraging steels, the maximum volume fraction of austenite was obtained after quenching and intercritical annealing. Dislocation densities computed on the base of mean-square microstrain values were about 10 11 cm −2 . These densities were systematically higher in martensite than in austenite, with very small differences between the weld metal and base metal.
17 citations
TL;DR: In this article, the authors evaluated the hardness response and the indentation creep of a 350 grade commercial maraging steel using a hot hardness tester and found that the hardness versus temperature plot exhibited three distinct regions.
Abstract: The hardening response and the indentation creep of a 350 grade commercial maraging steel were evaluated using a hot hardness tester. The hardness versus temperature plot exhibited three distinct regions. Hardness response was noted between 500–800 K. The unusually high values of activation energy and stress exponent obtained during the creep experiment could be rationalized by a novel concept of introducing a back stress term in the indentation creep relation. The corrected value of the activation energy was found to be reasonably in agreement with the activation energy for diffusion of Ni in iron. Results are supplemented with microstructural observation.
15 citations
TL;DR: In this article, the effect of temperature and strain rate on the 0·2% yield strength, ultimate tensile strength, and percentage elongation of M250 maraging steel was investigated under uniaxial tensile conditions in the temperature range from 25 (room temperature) to 550°C and the strain rate range 10−4−10−1 S−l.
Abstract: The effect of temperature and strain rate on the 0·2% yield strength, ultimate tensile strength, and percentage elongation of M250 maraging steel was investigated under uniaxial tensile conditions in the temperature range from 25 (room temperature) to 550°C and strain rate range 10−4–10−1 S−l. Up to 400°C the steel shows essentially strain rate insensitive behaviour with a gradual decrease in the 0·2% yield strength and ultimate tensile strength. The elongation remains constant at all strain rates up to 300°C. Fractographic analysis indicates that the increasing strain rate induces strain constraint resulting in an increased dimple size. An elongated structure was observed at temperatures above 400°C. X-ray diffraction reveals the presence of reverted austenite in the specimens tested at 550°C.MST/3263
9 citations
TL;DR: In this article, the thermal embrittlement behavior of 18Ni cobalt free (250 grade) maraging steel (T250) compared with 18Ni 8Co-5Mo (M250) was studied for different heat treatme...
Abstract: The thermal embrittlement behaviour of 18Ni cobalt free (250 grade) maraging steel (T250) compared with that of 18Ni–8Co–5Mo (250 grade) maraging steel (M250) was studied for different heat treatme...
8 citations
Patent•
09 Oct 1996
TL;DR: In this paper, a solution of nitrided and cold-warmed maraging steel is heated and held in a salt bath at 520 to 530 ° C for 10 to 25 minutes.
Abstract: (57) [Summary] [PROBLEMS] To provide a manufacturing technique in which a processing time is short, and good abrasion and durability are obtained. SOLUTION: A solution nitrided and cold worked maraging steel is heated and held in a salt bath at 520 to 530 ° C for 10 to 25 minutes, whereby a desired nitrided layer depth can be obtained on the surface. [Effect] Since the salt bath nitriding process time is 10 to 25 minutes, the required time is 1/10 to 1/20 as compared with the nitriding time of 4 to 6 hours by the conventional gas soft nitriding method, Productivity can be greatly increased.
8 citations
TL;DR: In this paper, the effect of hydrogen on Young's modulus was investigated in the case of type 304 steel and Fe-17Cr-15Mn alloy and it was shown that hydrogen-induced phase transformation depends on the austenite stability.
7 citations
TL;DR: In this article, a new internal friction peak caused by hydrogen in the maraging steel and compared it with those found in stainless steels which have so far been studied as typical engineering high-alloy materials.
Patent•
04 Nov 1996
TL;DR: In this article, a process for heat treating a hardenable, corrosion resistant alloy element is claimed and the steel alloy contains in weight%:- 47.4-82.4 Fe, 6-9 Ni, 11-15 Cr, 0.5-6 Mo+1/2W, 0-6 Co and/or Cu; 0-1 one or more from Ti, Nb, Al, Si, Mn, V, V; 0.1 rare earth and or mischmetals.
Abstract: Process for heat treating a hardenable, corrosion resistant alloy element is claimed. Maraging steel contains in weight%:- 47.4-82.4 Fe; 6-9 Ni;11-15 Cr; 0.5-6 Mo+1/2W; 0-6 Co and/or Cu; 0-1 one or more from Ti, Nb, Al, Si, Mn, V; 0-0.1 rare earth and/or mischmetals; 0-0.1 C and N; 0.1-0.5 Be. The steel alloy is also claimed.
Patent•
21 Nov 1996
TL;DR: In this paper, a maraging steel with a limited amount of C, Si and Mn is presented, and the alloy composition is controlled to Ti: 0.01% or less.
Abstract: (57) [Problem] To provide a maraging steel having improved toughness without increasing the amount of Ni. SOLUTION: Ni: 8.0 to 20.0%, Mo: 2. 0 to 10.0%, Co: 2.0 to 10.0% and A l: In a maraging steel containing 0.05 to 0.15%, a limited amount of C, Si and Mn, and the balance being substantially Fe, N: 0.005 to 0.05 3% is added and the alloy composition is controlled to Ti: 0.01% or less.
15 Jul 1996-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the composition fluctuation during spinodal decomposition in a 3.5 GPa steel was studied by Mo¨ssbauer spectroscopy and the aging reactions start with the redistribution of atoms, which results in the formation of Fe-Co-Rich zones and Ni-Mo-Ti-rich zones at the early stages of aging.
Abstract: The composition fluctuation during spinodal decomposition in a 3.5 GPa Fe-10%Ni-14%Mo-19%Co (wt.%) maraging steel was studied by Mo¨ssbauer spectroscopy. The aging reactions start with the redistribution of atoms, which results in the formation of Fe-Co-rich zones and Ni-Mo-Ti-rich zones at the early stages of aging. The redistribution of atoms is fast at the initial stages of aging and then becomes slow. Intermetallic compounds precipitate on the Ni-Mo-Ti-rich zones.
Journal Article•
Patent•
23 Feb 1996
TL;DR: Maraging steel contains in weight%:- 47.4-82.4 Fe; 6 9 Ni;11-15 Cr; 0.5-6 Mo+1/2W; 0-6 Co and/or Cu; 0 -1 one or more from Ti, Nb, Al, Si, Mn, V; 0 0.1 C and N; 0 1-0.5 Be as mentioned in this paper.
Abstract: Maraging steel contains in weight%:- 47.4-82.4 Fe; 6-9 Ni;11-15 Cr; 0.5-6 Mo+1/2W; 0-6 Co and/or Cu; 0-1 one or more from Ti, Nb, Al, Si, Mn, V; 0-0.1 rare earth and/or mischmetals; 0-0.1 C and N; 0.1-0.5 Be.