High Nitrogen Martensitic Steel for Critical Components in Aviation

Hucklenbroich, I.; Stein, G.; Chin, H.; Trojahn, W.; Streit, Edgar

doi:10.4028/www.scientific.net/msf.318-320.161

Cited by 13 publications

(7 citation statements)

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“…It can be achieved by using high nitrogen martensitic steels, where the sum of the carbon and nitrogen content is tuned between 0.6 and 0.8 %. Figure 6.5 shows the results of bearing life tests carried out on several high-strength steels with a rather high contact fatigue resistance (Cronidur 30, X30CrMoN15-1, containing 0.38 % N, 15 % Cr and 1 % Mo; it is used in the martensitic state) [9]. In case of ambient temperatures exceeding 200°C, other types of steels are required, such as the M series of the high-speed steels (e.g., AISI M2) that display the secondary hardening phenomenon.…”

Section: Steelsmentioning

confidence: 99%

Materials for Tribology

Straffelini

2015

Springer Tracts in Mechanical Engineering

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Section: Steelsmentioning

confidence: 99%

Materials for Tribology

Straffelini

2015

Springer Tracts in Mechanical Engineering

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“…High nitrogen martensitic stainless steel Cronidur 30 is the third-generation high performance bearing steel that successfully used in aerospace field, such as aviation turbine spindle bearing. [1][2][3][4] Nitrogen makes great contribution to the excellent corrosion resistance and mechanical properties of high nitrogen martensitic stainless steel, [5][6][7][8][9][10][11] and thus the nitrogen alloying is crucial in the manufacturing process. 12,13) The conventional nitrogen alloying method by adding nitrided alloy would contaminate the molten steel and induce the inhomogeneous distribution of nitrogen in the ingot.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen Solubility and Gas Nitriding Kinetics in Fe–Cr–Mo–C Alloy Melts under Pressurized Atmosphere

Feng

et al. 2022

ISIJ Int.

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The precise control of nitrogen content in high nitrogen martensitic stainless steel is the guarantee of its excellent performance, and is a crucial issue for its manufacturing process using pressurized gas nitriding. In this paper, the effects of nitrogen pressure, temperature and alloy composition on nitrogen solubility and pressurized gas nitriding kinetics of Fe-Cr-Mo-C alloy melts were investigated. In order to correct the deviation of nitrogen solubility from Sieverts' law under high nitrogen pressure, the first-and secondorder interaction parameters of nitrogen on itself were obtained; accordingly, the nitrogen solubility model under pressure was established and well verified. The nitrogen solubility decreased with increasing temperature and C content, and increased with increasing Cr and Mo contents. The nitrogen mass transfer in liquid phase was the nitriding rate-determining step under different nitrogen pressures. The apparent mass transfer coefficient of nitrogen was approximately 0.0218 to 0.0230 cm•s − 1 , and showed a weak dependence with pressure. The apparent mass transfer coefficient of nitrogen increased significantly with the increase of temperature and electromagnetic stirring, and was rarely affected by the content of Cr, Mo and C. Considering the influence of pressure change on nitriding rate in pressurization stage, a novel kinetic model for gas nitriding under high pressure was established and exhibited effectiveness in practice. KEY WORDS: high nitrogen martensitic stainless steel; pressurized atmosphere; nitrogen solubility; gas nitriding kinetics; mass transfer coefficient of nitrogen.

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“…AS one of the widely used aviation bearing materials in recent years, high nitrogen martensite stainless steel 30Cr15Mo1N exhibits high hardness, high strength and toughness, excellent corrosion resistance and fatigue performance, [1][2][3][4] for example, its fatigue life is 5 times that of M50, and the corrosion resistance is 100 times that of 440C. [5] Moreover, 30Cr15Mo1N steel has been successfully applied to the bearings of the fuel pump of space shuttle, the main bearings of aircraft engine, the ball screw of landing gear, the swash plate bearings of helicopter, and so on. [1,3,6,7] However, owing to the low cooling rate and the segregation of alloying elements during solidification process, the as-cast structure of stainless steel inevitably contains comparably excess and coarse precipitated phases.…”

Section: Introductionmentioning

confidence: 99%

Effect of Solidification Pressure on Phase Transformation and Precipitated Phases of 30Cr15Mo1N Ingot

Zhu

et al. 2021

Metall Mater Trans B

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In this research, the effect of solidification pressure on phase transformation temperature and sequence, amount of proeutectoid ferrite, characteristics of pearlite and carbonitrides have been investigated by microstructure observation, crystal structure and component analysis, and thermodynamic calculation. The microstructure of 30Cr15Mo1N ingot is mainly composed of martensite, austenite, pearlite, ferrite, M 23 (C,N) 6 and M 2 (C,N). With increasing solidification pressure, M 23 (C,N) 6 precipitation temperature, austenite (c) and ferrite (d) formation temperature increase, and M 2 (C,N) precipitation temperature and ferrite (a) formation temperature decrease. Under 0.5 MPa, the precipitation sequence during solidification process of 30Cr15Mo1N ingot is ''L fi d fi c fi M 2 (C,N) fi M 23 (C,N) 6 fi a + martensite/ retained austenite fi pearlite''. There is a negligible change in phase transformation sequence with increasing solidification pressure from 0.5 to 2 MPa. In addition, the increment in solidification pressure is beneficial to significantly increase the amount of proeutectoid ferrite and reduce pearlite lamellar spacing by enhancing cooling of 30Cr15Mo1N ingot. Meanwhile, with increasing solidification pressure from 0.5 to 2 MPa, the size of M 2 (C,N) and the amount of precipitated phases (pearlite and carbonitrides) have a decreasing trend, and the change in the size of M 23 (C,N) 6 can be neglected.

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High Nitrogen Martensitic Steel for Critical Components in Aviation

Cited by 13 publications

References 0 publications

Materials for Tribology

Materials for Tribology

Nitrogen Solubility and Gas Nitriding Kinetics in Fe–Cr–Mo–C Alloy Melts under Pressurized Atmosphere

Effect of Solidification Pressure on Phase Transformation and Precipitated Phases of 30Cr15Mo1N Ingot

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