Steel 1Cr18Ni9Ti Research Articles

The Effect of Welding Materials on 1Cr18Ni9Ti and 2Cr13 Steel Welding Joints Microstructure and Mechanical Properties

By method of TIG, under certain welding craft conditions, two kinds of welding wire were added,1Cr18Ni9Ti and 2Cr13 steel were welded. By (ZEISS) OM, SEM, the microstructure of two kinds of 2Cr13 and 1Cr18Ni9Ti welding joints were observed and analyzed, by electronic universal tensile machine, mechanical properties of welding joints were measured. The results show that 2Cr13 and 1Cr18Ni9Ti welded joints is typical columnar crystal, the microstructure is lath martensite + residual austenite + carbide; the micro-hardness of two kinds of welding joint changes fluctuantly, it increases firstly and reduces secondly, the value is up to max in welded joint zone. The welding joints filled in two kinds of materials, tensile samples rupture forms are toughness rupture; plasticity and strength of welding joint filled in ER308 welding material is better than that of welding joint filled in H1Cr21Ni10Mn7Mo welding wire. On the contrary, its hardness is lower than that filled in H1Cr21Ni10Mn7Mo welding wire.

A novel heat-resistant organic matrix adhesive for hydrophobic silica aerogels composites and 1Cr18Ni9Ti steel bonding

The novel organic matrix adhesive was used to join hydrophobic mullite fiber reinforced silica aerogels (HMF/SA) composites and 1Cr18Ni9Ti steel. It was prepared using silicone resin (SR) as a matrix, Al, low melting point glass (GP), ZnO and Fe2O3 powders as inorganic fillers, γ-aminopropyltriethoxysilane (γ-APS) as curing agent and dibutyltin dilaurate (DBTDL) as catalyst. The curing mechanism and character of the adhesive were studied, as well as the bonding mechanism of the adhesive. The tensile shear strength of the adhesive was investigated after heat-resistant experiment in atmosphere surroundings. Results showed that the adhesive could be cured at room temperature through polycondensation reaction using γ-APS. The adhesive had a good wettability with HMF/SA composites and 1Cr18Ni9Ti steel, and established strong adhesion between both of them. The adhesive could be resistant to 750°C with satisfactory bonding strength (4.68MPa). The optimized ratio of inorganic fillers had important influences on the bonding properties of the adhesive. Al took an important effect in giving a strong refractory ceramic bond to the adherends. Failure mode of joint was substrate failure due to the high chemical bonding force between the adherends.

The effect of nitriding at low temperatures on tribological and magnetic properties of austenitic stainless steel

The change of the structural and phase composition of the austenitic steel 12Cr18Ni10Ti is studied after nitriding in the plasma of a non-self-sustained low-pressure arc discharge at different temperatures. It is shown that, as a result of ion nitriding, it is possible to increase the microhardness and wear resistance of the investigated steel. The basic parameters of the nitriding process (temperature and composition of the gas mixture) that make it possible to improve the mechanical properties without significant changes in magnetic characteristics are selected.

Interaction of titanium with steel equipment in diffusion bonding

A model of reactive diffusion of carbon from steel equipment into titanium and of the interaction of steel equipment with titanium with the formation of an intermetallic compound is proposed. It is shown that the thickness of the titanium carbide layer formed in this process is more than an order of magnitude smaller than the thickness of the intermetallic layer. A kinetic criterion of the growth of the carbide layer, explaining its absence in the context of titanium with equipment made of 12Cr18Ni10Ti steel, is determined. The models are verified by experiments.

Research on Sticking Failure Characteristics of Cemented Carbide Blade

Through the analysis on damaged tool in sticking failure experiment by cutting austenitic stainless steel (1Cr18Ni9Ti) with scanning electron microscopy (SME), found that there are micro cracks existent on rake face near the tip of the cutting tool, through the research of the emergence, development and distribution direction of the crack, the direct reason for tool breakage is the crack being out of control. Combining the study of cutting tool element density change in cutting zone and grooving wear on rake face, this paper analyzed the cause of the binding between chip and tool and the influence factors of sticking failure during the cutting process.

Hydrogen Interaction with Stainless Steel 12Cr18Ni10Ti Containing Radiogenic 3He

Mechanical properties, structural changes and hydrogen interactions with stainless steel 12Cr18Ni10Ti subjected to accelerated radiogenic 3He buildup by means of “tritium trick” technique were studied. After saturation with tritium up to equilibrium concentration at a pressure 50 MPa and T=773 K the samples were rapidly cooled to room temperature and aged at this temperature up to the buildup of a predetermined 3He concentration. Kinetics of helium thermal release, hydrogen transport, trapping and accumulation in steel containing various concentration of 3He, synergistic influence of 3He and hydrogen on mechanical properties of steel containing up to 500 appm 3He and structural changes at various 3He concentrations are discussed.

Effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti stainless steel

Surface nanocrystallization of 1Cr18Ni9Ti austenite stainless steel was conducted by the supersonic fine particles bombarding (SFPB) technique. The friction coefficients and wear losses in air and vacuum were tested to analyse the effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti steel. The results show that the microstructure of the surface layer was refined into nano-grains successfully by SFPB treatment; furthermore, strain-induced martensitic transformation occurred during the treatment. The tribological properties of SFPB treated samples enhanced greatly, The dominant wear mechanism of the original 1Cr18Ni9Ti stainless steel is abrasive wear and adhesive wear, while it transfers to the combined action of fatigue wear, abrasive wear and adhesive wear after surface nanocrystallization by SFPB.

A Study on Machinability in Turning 1Cr18Ni9Ti Steel under Minimum Quantity Lubrication Machining

The present study show that metal cutting fluids changes the machinability because of their lubrication and cooling in turning 1Cr18Ni9Ti steel under minimum quantity lubrication (MQL) Machining. The experiments compares the mechanical performance of MQL to completely dry lubrication for the turning of 1Cr18Ni9Ti steel based on experimental measurement of cutting temperature, cutting forces, surface roughness, and dimensional deviation. Results indicated that the use of near dry lubrication leads to lower cutting temperature and cutting force, favorable chip-tool interaction, reduced tool wears, surface roughness, and dimensional deviation.

Hydrogen Interaction with Stainless Steel 12Cr18Ni10Ti Containing Radiogenic 3He

Hydrogen Interaction with Stainless Steel 12Cr18Ni10Ti Containing Radiogenic 3He

Microstructure and vacuum tribological properties of 1Cr18Ni9Ti steel with combined surface treatments

A sulfide film was fabricated on the nanocrystalline layer of 1Cr18Ni9Ti stainless steel by a two-step method of supersonic fine particles bombarding (SFPB) and low temperature ion sulfurization treatments. The microstructure and mechanical properties of the nanocrystallized surface and the sulfide film were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy (equipped with EDS), augur energy spectroscopy, X-ray photoelectron spectroscope, and nano-indenter. The tribological behaviour of the treated (after SFPB and sulfurizing treatments) 1Cr18Ni9Ti steel in vacuum was investigated on a ball-on-disk tribometer. The results showed that, randomly oriented equiaxial nanograins with the mean grain size less than 30nm were formed in the top surface layer of the SFPB treated sample, and a compact and uniform sulfide film mainly composed of FeS was obtained after the succedent sulfurizing treatment. Compared to the original 1Cr18Ni9Ti steel, the treated surface revealed lower friction coefficient and better wear resistance in vacuum, and the variation of tribological properties with atmospheric pressure of the treated samples was not significant. The dominant wear mechanisms of the treated 1Cr18Ni9Ti in vacuum were abrasive wear and fatigue wear.

Microstructural study of super Ni laminated composite/1Cr18Ni9Ti steel dissimilar welded joint

Super Ni laminated composite and 1Cr18Ni9Ti stainless steel were welded by the tungsten inert gas process with the Cr25–Ni13 filler alloy. The microstructure, element distribution and phase formation near the fusion zone were evaluated by standard technique. Results indicated the formation of four main regions: the fusion transition region on the 1Cr18Ni9Ti steel side, the fusion transition region on the super Ni laminated composite side, a columnar crystal weld region and the weld centre region. The microstructure on either side of the weld was characterized by strong directionality and changed from columnar austenite to equiaxed austenite in the weld centre. A Ni, Fe and Cr element transition region, about 30 μm wide, was formed at the fusion zone on the super Ni side. The phase formed into welded zone was composed mainly of austenite, δ-Fe, γ-Ni(Cr, Fe) and FeNi intermetallic compounds.

Properties of the Plasma Sprayed NiCrAlY+ (ZrO2+CaO) Graduated Coating on 1Cr18Ni9Ti Steel

The plasma sprayed gradated coating with the bottom layer of NiCrAlY and the top layer of (ZrO2+CaO) was prepared on the 1Cr18Ni9Ti steel surface by the plasma spraying technique. The phase structure and morphology of the gradated coating were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The high temperature oxidation resistance of the plasma sprayed samples at 800°C was investigated. The oxidation kinetics curve was worked out. The wear-resistance behavior of the graduated coating under dry sliding against GCr15 steel was evaluated on a ball-on-disc test rig. The results show that the thickness of gradated coating is about 320μm. The plasma sprayed gradated coating on stainless steel surface can improve the high temperature oxidation resistance of stainless steel. The oxidation rate of stainless steel is less than that of plasma sprayed gradated coating. The oxidation coating of plasma sprayed sample was very dense and is not easily exfoliated. The dense oxidation coating prevents the stainless steel from more oxidation. The friction coefficient of the 1Cr18Ni9Ti substrate was about 0.33 on dry sliding against the GCr15 steel, while the graduated coating experienced abated friction coefficient to 0.21 on the same testing condition.

Research on the Machinability of Hydrogenated Cylindrical Shell Materials (2.25 Cr-1Mo-0.25V Steel)

Firstly, with studying three typical aspects as cutting force, cutting temperature and chip breaking behavior, contrast experiments of machinability were made on hydrogenated cylindrical shell materials (2.25Cr-1Mo-0.25V), 45 steel, and stainless steel (1Cr18Ni9Ti). The experiment results show that the depth of cut ap have a larger effect on the main cutting force FZ and the cutting temperature θ than the affection of the feedrate f, for that reason, in order to reduce the main cutting force FZ and the cutting temperature θ, large feedrate situation will be better for machining work of hydrogenated cylindrical shell materials. When cutting hydrogenated cylindrical shell materials , many difficult points appearance, such as large cutting force, high cutting temperature, serious chips winding, chips difficult to break etc, which has worse machinability even than stainless steel(1Cr18Ni9Ti).

Friction and Wear Properties of SiC and Immerse the Copper Graphite Against 1Cr18Ni9Ti Friction Couples

Friction and wear properties of SiC and immerse copper graphite(C/Cu) against stainless steel (1Cr18Ni9Ti) friction couples were studied under room temperature and unlubrication by pin-disc tribometer. The test shows that at sliding speed of 0.56ms-1 and normal load of 5N, 20N, the SiC/1Cr18Ni9Ti friction coefficient decreases. The immerse copper graphite shows good friction and wear behavior at load 50N, at which the copper of graphite matrix is transported to the surface from the pore of graphite matrix to form a couple of copper and copper. It is difficulties to measure volume loss. When load increased, the copper was transported to generate the film and was grinded away continuously, which the immerse copper graphite(C/Cu) volume loss increases at load 120N. The results of comparing two couples show volume loss of the couple SiC/1Cr18Ni9Ti is severe, so it is not suitable to combine a couple. The couple of immerse copper graphite (C/Cu)/1Cr18Ni9Ti is better applied at low load.

Hydrogen diagnostics of structural states 18Cr10NiTi steel

The results obtained in the studies suggest the conclusion that the thermal desorption spectroscopy technique can be related to the methods enabling the estimation of the structural state of materials. The present paper reports the results from studies (hydrogen diagnostics) of structural states of materials, using 18Cr10NiTi steel as an example, the structure of which has been subjected to various actions such as reactive-element ion (N +, O +) implantation, cold extrusion deformation. The present results indicate that the use of thermodesorption spectrometry of hydrogen holds promise for estimating the structural condition of the metal and its changes under various actions.

Peculiarities of plastic flow involving “deformation waves” observed during low-temperature tensile tests of highly irradiated 12Cr18Ni10Ti and 08Cr16Ni11Mo3 steels

In a previous paper, it was shown that the expectation that neutron irradiation of low-nickel austenitic steels leads to a low saturation level of ductility is not always valid. At high dose ductility is observed first to decrease with dpa during room temperature testing and then under some conditions to increase at higher dose. This produces anomalously high deformation arising from a previously unrecognized mechanism that precludes sustained necking and produces a moving deformation front. It was earlier speculated that this behavior is a result of α-martensite formation in the deforming region. New studies involving testing over −115 to +120 °C confirm that the γ → α transformation is involved with this deformation mechanism and is the cause of the recaptured ductility. When the irradiated alloy has not yet reached the dose threshold of wave initiation at room temperature a decrease in test temperature can induce wave generation, consistent with the known effect of temperature on martensite instability.

Experimental Investigations of Tool Wear Mechanisms in Machining 1Cr18Ni9Ti Stainless Steel

The purpose of this investigation is to recognize the wear mechanisms of cemented carbide tools in dry hard turning of stainless steel (1Cr18Ni9Ti). From the view point of machining, stainless steels are often considered as poor machinability materials. Turning tests were carried out by using a CA6140 lathe and a cutting force measuring device. For this purpose, both microscopic and microstructural aspects of the tools were taken into consideration. Meanwhile, the cutting forces are also measured in the experiment. The chips were analyzed by scanning electron microscopy. The machinability of 1Cr18Ni9Ti austenitic stainless steels is examined in terms of tool life and cutting parameter presented in this paper. Results show that cutting forces vary greatly with the experimental cutting parameters. Analysis indicated that tool wear mechanisms observed in the machining tests involve abrasion wear, thermal and fatigue shock wear and adhesive wear.

Prediction of swelling of 18Cr10NiTi austenitic steel over a wide range of displacement rates

The internal components of pressurized water reactors of Russian types WWER-440 and WWER-1000 are constructed of annealed 18Cr10NiTi steel, a close analog to AISI 321. Void swelling of the internals is a concern for plant life extension and predictive equations are required to assess the potential of swelling in critical components such as the baffle ring or reflection shield that surrounds the WWER core. The only previously available swelling data for this steel were derived at higher than PWR-relevant displacement rates in the BOR-60 fast reactor. The swelling equation previously developed from these data does not incorporate the effect of displacement rate on swelling. Using heavy-ion irradiation at very high dpa rates (10 � 2 and 10 � 3 dpa s � 1 ) and doses (5–100 dpa) and coupling the results to available neutron data a swelling equation has been developed that specifically incorporates the effect of dpa rate on void swelling. Experimental results allow description of the swelling peak, the incubation period and the steady-state swelling rate over a wide range of irradiation temperature. For the first time it appears possible to describe both ion and neutron data on this steel within the framework of a single empirical model. Swelling maps constructed from this model permit forecasting of the behavior of the steel in WWERs under the required irradiation conditions, not only at already attained exposure doses, but more importantly to higher dose levels that will be reached following plant life extension.

The X-Ray Diffraction Characteristics of Different Materials

The x-ray diffraction characteristics of different materials are discussed in this paper. It is found that the accurate determination of real stress is not easy to obtain when two diffraction peaks with low diffraction intensity are shown and the residual stress of stainless steel, aluminum, titanium alloy materials etc are determined by X-ray method. Five kinds of uniform intensity girders made from common carbon steel (Q235), austenite stainless steel (1Cr18Ni9Ti), martensitic stainless steel(A335P92), aluminium alloy(LY12) and titanium alloy(TA15) are determined repeatedly using uniform intensity girder demarcation method. It is proved by experiment results that X-ray diffraction peaks at some angles can’t well reflect the real change of stress.

Effect of Free-cutting Additives on Machining Characteristics of Austenitic Stainless Steels

The machinability tests were conducted by using a YD-21 dynamometer on a CA6161A lathe. The experiments were conducted to determine the effect of free-cutting additives on machining characteristics of austenitic stainless steels. The conventional austenitic stainless steel 1Cr18Ni9Ti (steel A) and the free cutting austenitic stainless steel (steel B) were prepared. The results have shown that machinable inclusions were composed of MnS and CuO, and they might be also Ti4C2S2. The presence of Bi in the inclusion was detected by the atom map and electro-probe microanalysis (EPMA), which might be one of the most important factors to improve the machinability of austenitic stainless steels. The cutting forces for steel B were lower than those of steel A at various cutting speeds; the abrasion depth of the flank of the tool for steel B was less than that of the steel A under the same cutting conditions. The machinability of austenitic stainless steel was visibly improved by adding free-cutting additives, such as S, Cu and Bi. Ultimate tensile, yield strength, and total elongation values of the free cutting austenitic stainless steel were improved due to the addition of these free-cutting additives.