CORROSION AND CAVITATION RESISTANCE IN SEAWATER OF CHROMIUM–NICKEL–MANGANESE HIGH-STRENGTH NITROGEN AUSTENITIC STEELS

Corrosion and cavitation resistance in seawater of high-strength economically alloyed nitrogen chromium–nickel–manganese steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N is experimentally studied compared to chromium-nickel steels Cr18Ni9 and Cr18Ni9N. Tests for resistance to pitting corrosion were carried out according to the chemical method in the test solution 100 g/l FeCl3 ·6H2 O. Resistance to general corrosion was assessed by tests in synthetic seawater (3 % NaCl). Test for cavitation resistance in seawater was performed using a research stand of high-intensity cavitation effects with the use of ultrasonic devices UIP 1000 hd Hielscher Ultrasonic in 3 % NaCl solution in water at a frequency of 20 kHz, a power of 1000 W and amplitude of 25 microns for 8 – 36 hours. The extent of damage and change in the surface microhardness, change in the phase composition and mass of the samples were assessed after cavitation. It is shown that steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N are more susceptible to pitting in seawater and in solution of ferric chloride, and have the general corrosion rate lower than that of chromium-nickel steels type Cr18Ni9. It is shown that ultrasonic cavitation can not only lead to surface damage due to erosion, enhance local corrosion, but also to changes in their physico-mechanical properties by strain hardening and phase transformations. Steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N with thermally and mechanically stable austenite are more resistant to ultrasonic cavitation in the seawater in comparison with chromium-nickel steels, especially those with less strength and less resistant steel Cr18Ni9. So subjected to cavitation in the seawater for 36 hours, samples of chromium-nickel steels Cr18Ni9 and Cr18Ni9N had a significant change in their condition: significant damage (etching) and surface hardening, and there was formation of a small amount of martensite in steel Cr18Ni9. Samples of steels Cr19Mn10Ni6Mo2N and Cr19Mn10Ni6Mo2Cu2N had only minor changes in surface conditions and hardening of the surface layers.

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AMPCOLOY 83

Alloy Digest ◽

10.31399/asm.ad.cu0310 ◽

1976 ◽

Vol 25 (3) ◽

Keyword(s):

Thermal Conductivity ◽

Corrosion Resistance ◽

Precipitation Hardening ◽

Base Alloy ◽

High Strength ◽

Heat Treating ◽

General Corrosion ◽

Copper Base ◽

Resistance To Wear ◽

Copper Base Alloy

Abstract AMPCOLOY 83 is a wrought copper-base alloy containing nominally 1.8% beryllium. It offers good formability in the unhardened condition and can be strengthened by precipitation hardening. It has a combination of high strength and hardness, good ductility, good electrical and thermal conductivity, excellent resistance to wear and fatigue, and high resistance to general corrosion. Among its many uses are components for resistance welding, bushings and shafts. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-310. Producer or source: Ampco Metal Inc..

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AMBRALOY 928

Alloy Digest ◽

10.31399/asm.ad.cu0069 ◽

1958 ◽

Vol 7 (10) ◽

Keyword(s):

Corrosion Resistance ◽

Shear Strength ◽

Aluminum Alloy ◽

Physical Properties ◽

Tensile Properties ◽

High Strength ◽

General Corrosion ◽

Copper Aluminum

Abstract AMBRALOY-928 is a copper-aluminum alloy having high strength, hardness and excellent resistance to general corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Cu-69. Producer or source: American Brass Company.

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ALLVAC 13-8

Alloy Digest ◽

10.31399/asm.ad.ss0866 ◽

2002 ◽

Vol 51 (11) ◽

Keyword(s):

Stainless Steel ◽

Precipitation Hardening ◽

Cold Working ◽

High Strength ◽

Heat Treating ◽

General Corrosion ◽

Single Treatment ◽

Good Resistance ◽

Temperature Performance ◽

Very High

Abstract Allvac 13-8 has good fabricability and can be age hardened by a single treatment in the range 510-620 deg C (950-1150 deg F). Cold working prior to aging enhances the aging. This martensitic precipitation-hardening stainless steel has very good resistance to general corrosion and stress-corrosion cracking. It develops very high strength and exhibits good transverse ductility and toughness in heavy sections. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-866. Producer or source: Allvac Metals Company.

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ALLEGHENY LUDLUM TYPE 205

Alloy Digest ◽

10.31399/asm.ad.ss0640 ◽

1997 ◽

Vol 46 (10) ◽

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Corrosion Resistance ◽

Physical Properties ◽

Tensile Properties ◽

Magnetic Permeability ◽

Cold Working ◽

High Strength ◽

Heat Treating ◽

Austenitic Steels

Abstract Allegheny Stainless Type 205 is a chromium-manganese nitrogen austenitic high strength stainless steel that maintains its low magnetic permeability even after large amounts of cold working. Annealed Type 205 has higher mechanical properties than any of the conventional austenitic steels-and for any given strength level, the ductility of Type 205 is comparable to that of Type 301. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SS-640. Producer or source: Allegheny Ludlum Corporation. Originally published March 1996, revised October 1997.

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AVESTA SHEFFIELD SAF 2507

Alloy Digest ◽

10.31399/asm.ad.ss0652 ◽

1996 ◽

Vol 45 (9) ◽

Keyword(s):

High Resistance ◽

Stainless Steels ◽

Coefficient Of Thermal Expansion ◽

Austenitic Stainless Steels ◽

High Strength ◽

Heat Treating ◽

General Corrosion ◽

Temperature Performance ◽

Chloride Stress Corrosion Cracking ◽

Very High

Abstract Avesta Sheffield SAF 2507 is an austenitic/ferritic duplex stainless steel with very high strength. The alloy has a lower coefficient of thermal expansion and a higher thermal conductivity than austenitic stainless steels. The alloy has a high resistance to pitting, crevice, and general corrosion; it has a very high resistance to chloride stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-652. Producer or source: Avesta Sheffield Inc.

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AVESTA 2205 CODE PLUS TWO

Alloy Digest ◽

10.31399/asm.ad.ss0472 ◽

1993 ◽

Vol 42 (3) ◽

Keyword(s):

Corrosion Resistance ◽

Stress Corrosion ◽

Heat Exchangers ◽

High Strength ◽

Heat Treating ◽

Pressure Vessels ◽

General Corrosion ◽

Duplex Microstructure ◽

Good Resistance ◽

Desalination Plants

Abstract AVESTA 2205 is a ferritic-austenitic duplex stainless steel. It resists stress-corrosion cracking very well and has good pitting and general corrosion resistance. Its high strength and stress-corrosion resisting characteristics are a reflection of its duplex microstructure. Its uses include heat exchangers, desalination plants, and pressure vessels that need good resistance to corrosion. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-472. Producer or source: Avesta Sheffield Inc. Originally published July 1986, revised March 1993.

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Influence of grain size and ?-phase stability on the fatigue limit of high-strength austenitic steels

Metal Science and Heat Treatment ◽

10.1007/bf00700551 ◽

1981 ◽

Vol 23 (5) ◽

pp. 354-359

Author(s):

E. I. Shchedrin ◽

V. V. Sagaradze ◽

K. A. Malyshev

Keyword(s):

Grain Size ◽

Fatigue Limit ◽

Phase Stability ◽

High Strength ◽

Austenitic Steels

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The impact of neutralizer-free ignition of a radio frequency ion thruster on the lifetime of the ion optics system

International Journal of Modern Physics A ◽

10.1142/s0217751x21400170 ◽

2021 ◽

pp. 2140017

Author(s):

Long-Fei Ma ◽

Li Duan ◽

Jian-Wu He ◽

Qi Kang ◽

Keyword(s):

Radio Frequency ◽

Pyrolytic Graphite ◽

High Strength ◽

Surface Damage ◽

External Source ◽

Ion Thruster ◽

Neutral Gas ◽

Discharge Ignition ◽

Ion Optical System ◽

The Impact

In the initial stage of a radio frequency ion thruster (RIT) ignition, an influx of electrons is required from an external source into the discharge chamber and ionization of the neutral gas propellant. A neutralizer-free method for Townsend breakdown discharge ignition based on Paschen’s law was developed in this study. The feasibility of the ignition method was confirmed by performing thousands of ignition experiments. Metallic Molybdenum (Mo), pyrolytic graphite (PG) and Zr[Formula: see text]Ti[Formula: see text]Cu[Formula: see text]Ni[Formula: see text]Be[Formula: see text]alloy acceleration grids were prepared, and ignition-induced damage on the grids was investigated. A field-emission scanning electron microscope was used to inspect surface damage on the grids after multiple ignitions and to analyze the influence of the ignition method on the lifetime of the ion optical system. Grid materials for space missions that require multiple RIT ignitions (10[Formula: see text] should be high-strength blocks that are resistant to sputtering corrosion and high temperature.

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