Academic literature on the topic '10CrMo9-10 steel'

Liquid metal embrittlement ( LME ) is a phenomenon , where liquid (molten ) metal is mostly intergranulary (but not only ) penetrated into solid metal and causes its brittle fracture. The LME is usually related to low melting metals (zink, tin , cadmium ...) ,which are in the contact with higher molten ones ( steels, Ni alloys...). Cases of LME as a Cu penetration into pipeline welded joint of 15G2S steel ,a hot temperature corrosion in the cement works shell plate made of AISI 310 stainless steel attacted by Ni3S2 (Ts= 644°C) and a vanadium corrosion in the boiler vessel (10CrMo9-10 steel) due to V2O5 + Na2SO4 eutecticum (~600°C ) are concerned.

The purpose of the paper was to analyse the effect of diverse heat treatment parameters (normalising and tempering) on mechanical characteristics of the material used to develop ϕ508x20 tube bends made of the 10CrMo9-10 steel by application of induction heating. The research conducted included tests of basic mechanical properties as well as low cycle fatigue and creep at the temperature of 500°C. With reference to the results thus obtained, it has been established that there is a relationship between mechanical properties of bends and individual features of their microstructure conditional to the heat treatment parameters. Among other conclusions drawn in the research, it has been found that the main structural factor conditioning the mechanical properties of bends was the grain size. Heat treatment parameters characterised by lower temperature and shorter tempering time triggered changes in the material microstructure, such as increased grain comminution. The effects of the said changes included improvement of strength characteristics (Rm, Rp0,2) as well as increased material durability under conditions of fatigue and creep. Main criterion-specific mechanical properties and geometric features of the bends developed conformed with the relevant requirements of reference standards (PN-EN 10216-2, PN-EN 12952).

The paper presents results of X-ray measurements of the texture of a magnetite (Fe3O4) layer formed on 10CrMo9-10 steel during 100,000 hours operation at the temperature of 575°C (in a flowing medium environment). The formed oxide layer was ≈140µm thick. Measurements of texturing were performed on the oxide surface and also at the depth of ≈50µm from the surface (1st polishing) and ≈100µm (2nd polishing). X-ray studies were carried out using the radiation of a cobalt anode tube, λCo=0.17902nm, for (311) and (400) Fe3O4 reflections, using a radiation beam collimated to φ=2mm. The study was aimed at determination of correlation between the texturing and the structure on the magnetite layer cross-section. A clear texturing of {111} and {111} type for the magnetite in the initial state and after the second polishing was found. Instead, after the first polishing there was a substantial texturing of {034} and {015} type. A different nature of the texture may result from a diversified morphology of magnetite at various depths (caused inter alia by a differentiated temperature on the tube wall cross-section during the material operation), which is related among other things to the crystallites size. The magnetite structure and texture changes can affect the magnetite porosity and cleavage.

Abstract The paper contains results of studies into the formation of oxide layers on 10CrMo9-10 (10H2M) steel long-term operated at an elevated temperature (T = 545°C, t = 200,000h). The oxide layer was studied on a surface and a cross-section at the inner and outer surface of the tube wall on the outlet both on the fire and counter-fire side of the tube wall surface. The obtained results of research have shown a higher degree of degradation, both of the steel itself and oxide layers, on the fire side. In addition, it has been shown that on the outside tube wall, apart from iron oxides, there are also deposits composed mainly of Al2SiO5.

Purpose: The main goal of the work is to determine the influence of the parameters of stress relief annealing on the mechanical and structural properties of welded joints made of chromium-molybdenum type 10CrMo9-10 steel. Design/methodology/approach: In the study, commercial 10CRMO9-10 steel was used, the Polish equivalent of 10H2M. This is a chromium-molybdenum toughened steel, i.e. after normalization (910-960°C) and high tempering (650-780°C). The materials were subjected to heat treatment, tests of mechanical properties, Charpy impact test, hardness of individual material zones, as well as macro and microscopic observations. Findings: The hardness tests indicated, that materials subjected to a single heat treatment possess the greatest hardness. Materials undergoing several heat treatments, possess hardness on a similar level to materials that have been annealed once, however they are characterized by low reproducibility of results. The most important parameter of heat treatment of the tested steel is heating up to a temperature of 690°C. Due to such heating, optimal mechanical properties are achieved, which results in long and safe exploitation of the produced elements. Research limitations/implications: The processes of heat treatment are very important to achieve optimal strength properties of welded joints. Practical implications: The development of energy worldwide has caused the creation of machines working in higher pressure and temperature ranges. The influence of temperatures decreases the service life of a given element. The adaptation and completion of the appropriate process of heat treatment extends the exploitation time of elements. Originality/value: Determining the mechanical properties of 10H2M steel, dependent on the temperature of heat treatment and heating time. It was concluded that the optimal parameter of heat treatment for the tested materials – is heating at a temperature of 690°C.

The numerical analysis results of bending with local induction heating of 10CrMo9-10 steel tubes have been presented in the paper. The goal of conducted simulations was to determine the process parameters that allow to obtain tube bends with geometric features which meet requirements of relevant standards. The risks of wrinkling, excessive tube bend ovalization and cracking (according to Cockroft-Latham criterion) have been analysed. The obtained results prove that numerical modeling can be used to minimize the costs of tube bending technology implementation without the need of further process parameters corrections.

Destructive testing of creep exposed components is a powerful tool for evaluation of remaining lifetime of high temperature pipe systems. The most common destructive evaluation method used today is uniaxial creep testing. Uniaxial creep tests can produce accurate creep curves but the test method has some drawbacks such as costliness and long testing times. It also demands large sample material outtake which often involve weld repair. Impression creep (IC) testing is a relatively new alternative test method for evaluating primary and secondary creep rates. The scope of this work is to evaluate the benefits and drawbacks of IC testing over uniaxial creep testing in order to determine its usefulness as a test method. A literature survey was carried out over the area creep testing of high temperature pipe systems, with particular focus on impression creep testing. The result of the literature survey clearly showed several benefits with impression creep testing. An IC test series was performed in order to determine the secondary creep rate of a service exposed 10CrMo9-10 high temperature pipe steel. The IC tests were performed by VTT in Finland, using the same test parameter and sample material as in previous projects where the creep properties of the test material were determined by uniaxial creep testing. The result of the predicted secondary creep rate obtained from the IC tests was compared with the secondary creep rates measured during the uniaxial tests. The IC tests results did not align satisfactory with the results from the uniaxial creep tests, which would have been expected. The reason for this may be due to sources of error during impression creep testing, since very small displacements due to creep have to be measured with high precision during the tests. Further testing of the impression creep test method is recommended as a result of this work, in order to evaluate the method.
Förstörande provning av krypexponerade komponenter är ett kraftfullt redskap för utvärdering av återstående livslängd hos rörsystem med höga drifttemperaturer. Den vanligaste formen av förstörande provning i dessa fall är idag enaxlig krypprovning. Enaxliga krypprovningar producerar fullständiga krypkurvor men provningsmetoden har vissa nackdelar såsom att den är relativt dyr och tar förhållandevislång tid. Impression creep eller (IC) –provning är en relativt ny, alternativ, testmetod för att utvärdera primär och sekundärkryp. Det här arbetet ämnar utreda för- och nackdelar med IC-provning gentemot enaxlig krypprovning, samt undersöka dugligheten av IC-provning som testmetod. En litteraturstudie över området provning av krypegenskaper hos rörsystem med höga drifttemperaturer, med extra fokus på IC-provning har genomförts. Resultatet av litteraturstudien pekade tydligt på fördelarna med IC provning. En serie IC-tester utfördes också i syfte att bestämma den sekundära kryphastigheten hos ett driftpåkänt 10CrMo9-10 låglegerat tryckkärlsstål avsett för höga drifttemperaturer. IC-provningen gjordes av VTT Finland. Samma testparametrar och samma provmaterial som hade använts i tidigare projekt där krypegenskaperna hos provmaterialet har utvärderats bl.a. genom enaxlig krypprovning. Resultaten från IC-provningen jämfördes med de sekundära krypningshastigheterna som hade observerats vid den enaxliga krypprovningen. Resultaten från IC-provningen visade sig avvika från resultateten från den enaxliga krypprovningen. Orsaken till det kunde inte förklaras. Mätningar av mycket små förskjutningar samt små temperaturavvikelser föreslogs eventuellt kunna leda till felkällor. Som ett resultat av det här arbetet förslås fortsatt utvärdering och provning med IC-metoden behövs innan provningsmetoden kan tas i bruk.