This diploma thesis studies the structure of selected austenitic stainless steels which were fatigued at room and depressed temperatures. The theoretical part is divided into three parts. The first one defines the austenitic stainless steels with accent to their chemical composition and microstructure. Second part is dedicated to deformation-induced martensite formation. The third part shows the mechanisms and stages of damage due to cyclic straining. The experimental part is focused especially on the observing of microstructural changes by methods of colour metallography and their relation to stress-strain response of material under selected conditions of fatigue loading. Series of samples of 304 and 316L steels were prepared by colour etching and their microstructures were documented using optical microscopy. Then the semi-quantitative measurements of presence and morphology of deformation-induced martensite were done and the results were discussed and correlated with fatigue damage level.

M. Tech. (Department of Metallurgical Engineering, Faculty of Engineering and Technology), Vaal University of Technology. / The production of austenitic stainless-steel pump impellers in foundries present a huge challenge mainly due to its thin-walled blades, pouring temperature, presence of junctions and chemical composition. Two different alloys were used namely nodular cast iron and austenitic stainless-steel. Nodular cast iron was used as a comparison alloy due to its excellent flowability whereas austenitic stainless-steel was chosen due to its attractive corrosion and wear resistant properties. Austenitic stainless-steel alloy showed difficulties during casting because of its chemical composition and freezing range. Thin-walled sections are more susceptible to filling defects like misrun and cold-shut. This results in high scrap rate and high processing costs during high production of thin-walled components. High pouring temperature is considered one of the most effective methods to improve filling ability of thin-walled castings. However, there is a major drawback in using this method owing to the high occurrence of shrinkage defects and hot tearing especially at junctions. 1060 aluminium was used as a benchmark to evaluate the effect of wall thickness on the filling and feeding of thin-walled Al components with complex geometry during sand casting. The aim of this dissertation is therefore to optimize casting process of sand cast austenitic stainless-steel pump impeller. Numerical modelling and additive manufacturing were used to optimize the production of this product. The use of casting simulation software combined with three-dimensional (3D) mould printing technology has enabled optimisation of casting parameters to minimise the occurrence of casting defects. Casting parameters of five test samples of complex geometry and varying thicknesses (1.0 mm;1.5 mm;2 mm;2.5 mm and 3.0 mm) were optimised using MAGMAsoft® at a constant pouring temperature of 700 °C and 1060 Aluminium as an alloy. Simulation and casting results showed that complete filling was only possible at a wall thickness of 3 mm. The simulation results showed that as the wall thickness increased from 1 mm to 3 mm the filling ability increased by 67.5 % whereas experimental casting results showed that filling ability increase by 75 %. The combination of MAGMAsoft® simulation and 3D printed moulds proved to be effective tools in predicting filling and feeding of thin-walled aluminium components during sand casting. MAGMAsoft® casting software was used to simulate metal flow and predict the degree of filling at different pouring temperatures. Test samples were cast using 1060 Aluminium alloy at temperatures of 702 °C, 729 °C, 761 °C, 794 °C, 800 °C and 862 °C. Complete mould filling was predicted at 800 °C using the simulation model and 761°C during actual casting. At temperatures above 761°C tearing at the junction was quite pronounced. An optimal of 761°C pouring temperature was found to be appropriate pouring temperature when casting thin-walled aluminum components using sand casting. MAGMAsoft® casting software proved to be an effective tool in optimizing filling and feeding of thin-walled aluminium components during sand casting. Nodular cast iron pump impeller was optimized at 1500 °C using MAGMAsoft® and 3D mould printing technology. Design variables used were feeder radius (17 mm, 18 mm, 19 mm and 20 mm), feeder height (32 mm, 33 mm, 34 mm, 35 mm) and number of feeders of (3, 4 and 5). Simulation and casting results showed a completely-filled casting. The high fluidity of nodular cast iron promotes mould filling ability and prevent any form of misrun defect. Minimum shrinkage was noted at the junctions and top surface of the casting. A new design was proposed to eliminate shrinkage defects at the junctions of the nodular cast iron pump impeller. The design used a tapered circular runner bar with straight ingates. Optimization of nodular cast iron was now done at 1390 °C with the use of MAGMAsoft® and real casting was done 1385 °C. Simulation and casting were in correlation to each other since both showed completely-filled mould cavity with no misrun, cold-shut and shrinkage porosity defect. Simulation proved to be an effective tool in optimizing filling and solidification of nodular cast iron during sand casting. Austenitic stainless-steel pump impeller was optimized at 1500 °C using MAGMAsoft® and 3D mould printing technology. A high quality mould and core print were printed with the use of Voxeljet VX1000 at a minimum period of time. Design variables used were feeder radius (17 mm, 18 mm, 19 mm and 20 mm), feeder height (32 mm, 33 mm, 34 mm, 35 mm) and number of feeders of (3, 4 and 5). An increase in feeder size and the number of feeders greatly reduced hot spot and porosity of the casting but it also reduced the casting yield. The quality of the casting was found to be inversely proportional to the casting yield. Simulation showed a completely-filled casting with actual casting showing only 50 % filling ability. High viscosity of the molten metal and thin walled blades promote quick solidification which caused misrun defects. A new design was proposed to eliminate misrun defects of the first design. MAGMAsoft® was used to optimize this design at 1550 °C. The design used a tapered circular runner bar with tapered ingates. The actual casting showed improved filling ability from 50 % to 80 % while simulation showed completely-filled mould cavity (100 %). Major factors which contributed to low filling ability of austenitic stainless-steel pump impeller were chemistry, runner system and men. Numerical modelling and additive manufacturing did optimize filling and feeding of sand cast austenitic stainless-steel pump impeller.

Friction stir processing (FSP) has been utilized to locally process regions of arc weldments in 304L stainless steel to improve the microstructure and mechanical performance. The cast microstructure and coarse delta-ferrite has been replaced with a fine-grained wrought microstructure. Furthermore, twins were introduced throughout the friction stir processed region. Although sub-surface sigma and carbides were introduced during FSP, their presence is not expected to adversely affect the resulting mechanical or corrosion properties of friction stir processed 304L arc welds. The resulting mechanical properties of FS processed weldments were also an improvement over as-welded arc welds. FSP resulted in an increase of 6% for both yield and ultimate strength. It is expected that the improved microstructure will lead to improved stress corrosion cracking and general corrosion properties.

This thesis is meant to serve as part of a competence platform for future product development projects at Sandvik Coromant AB, Solid Round Tools Department, Västberga, Sweden. The project objective is to gain generic knowledge of the wear mechanisms that restrict tool lifetime when drilling austenitic stainless steel. Thus, identifying if the weakest link of the tool is located within the coating, the coating adherence or in the strength of the substrate. A theoretical review of the work-piece and tool materials has been conducted as a background, along with definition of tool geometry and process parameters. Furthermore, the review includes chemical and process design effect on mechanical properties of the austenitic stainless steel, TiAlN coatings and cemented carbide substrates. Additionally, the basic principles of the wear mechanisms and wear types that are specific to drilling have been reviewed. During the experimental procedures both solid and exchangeable tip drills from cemented carbide with multilayered PVD TiAlN coatings were tested. Two series of tests were conducted, the first series aimed to identify wear type dependency on cutting speed, focusing on wear of the tool margin. The second test series was performed to map the wear progression depending on distance. Analyses including identification the main wear mechanism, quantification the amount of wear, identify wear location on the tool, crack investigation and WDS analysis of chemical wear. Adhesive coating wear was found on the tool margin at an early stage. The adhesive wear rapidly progressed into a stable intermediate stage. Leaving the substrate exposed and more susceptible to other wear types resulting in crack and oxide layer formation.

No description available.

Este estudo apresenta uma tentativa para investigação do efeito que a sensibilidade à taxa de deformação do material poderia provocar no modo de falha do ponto de solda. É sabido que alguns materiais quando deformados dinamicamente sofrem elevação na sua resistência mecânica, e portanto este aumento poderia afetar o comportamento, ou seja, o modo de falha da junta. Os modos de falha esperados neste estudo são o de cisalhamento do ponto na interface ou o arrancamento do ponto na região da zona termicamente afetada. Uma formulação analítica para as tensões atuantes devido à solicitação dinâmica no ponto foi proposta com base em estudos existente para juntas solicitadas estaticamente. Propôs-se uma forma de quantificar a taxa de deformação, que foi incorporada à formulação da tensão dinâmica atuante na região da junta. Em conjunto à formulação analítica, um modelo de elementos finitos foi desenvolvido e diversas condições de carregamento e geometrias foram analisadas e posteriormente comparadas com os resultados analíticos. Como resultado principal verificou-se que, para a estimativa adotada para a taxa de deformação de material, o modo de falha da junta não se altera quando comparado com o modo de falha presente na junta solicitada a carregamento estático. E que para as formulações estimadas e modelos investigados a falha teria uma tendência a ocorrer na região da zona termicamente afetada para qualquer dos casos de carregamento analisados. / This study presents an attempt to probe the effect that some materials strain rate sensitivity could set in the failure mode of the spot weld joint. It is well known that some materials when dynamically loaded and deformed have its mechanical strength increased and therefore this strength increase could affect the joint failure behavior. The failure modes taken in account in this study are the shear of the spot weld in the interface region and the pull-out of the spot weld in the heat affected zone. An analytical formulation to the acting stress in the spot weld region owing to the dynamic loading has been proposed based on studies performed to the statically loaded spot weld joint. Moreover, an analytical formulation has been proposed to quantify the strain rate, and it has been incorporated in the dynamic stress formulation. A finite element model has been also built. Several geometrical configurations of this model have been analyzed under several velocity loading conditions, and their results have been compared with the analytical considerations. As the main result, it has been verified, to the estimated strain rate formulation, the failure mode in the dynamic loading condition has not effectively changed in comparison with the statically loaded joint failure. And according to the formulation considered and the finite elements models results the failure would tend to happen in the heat affected zone to any of the loading cases taken in account in this study.

O aço especial UNS S31254 (aço 254), um aço inoxidável austenítico contendo 20,1% de cromo, 18,4% de níquel e 6,42% de molibdênio foi estudado com o objetivo de ser aplicado em técnicas eletroanalíticas, tais como a potenciometria, a condutimetria e como eletrodo indicador em medidas de pH. Os estudos eletroanalíticos foram precedidos de curvas de polarização potenciostáticas e potenciodinâmicas e de ensaios não eletroquímicos (FTICR, MEV e XPS), em que se caracterizou a presença do filme passivante. Grande parte dos estudos incluíram, para efeito de comparação, os aços UNS S 31603 (aço 316 L) e UNS S31678 (aço F 138), o primeiro de largo emprego comercial e o último, aplicável em implantes ortopédicos. Os estudos, realizados a 25° C, se iniciaram com a caracterização eletroquímica dos referidos materiais imersos em meios aquosos de ácidos clorídrico, acético, nítrico, sulfúrico e galacturônico, e dos sais cloreto de sódio, sulfato de sódio e nitrato de sódio, variando-se a concentração do eletrólito. O aço 254 se mostrou passivado, na grande maioria dos meios estudados, em toda a faixa de potenciais que se estende do potencial de corrosão (Ecorr, potencial de circuito aberto estacionário) até o potencial de transpassivação (onde ocorre o rompimento do filme e, na maioria dos meios, a oxidação generalizada da superfície e a reação H2O/O2). Em meio de ácido acético a faixa de potencial em que o referido aço se mantém passivado é a mais ampla, indicando que o rompimento do filme passivo exige maior energia, em virtude do maior teor de molibdênio superficial detectado por MEV. A corrosão por pite foi observada em meios de HCI e de NaCI a potenciais mais positivos do que o de transpassivação. A caracterização da superfície por MEV mostrou que as inclusões presentes no aço são constituídas basicamente de óxidos de alumínio e de cálcio. A análise por XPS da superfície do aço 254 apenas polido e exposto ao ar revelou a presença de Mo (VI) na superfície; em meio de NaCI 0,15 mol L-1 há o enriquecimento gradual de Mo (VI) quando se varia o potencial desde o Ecorr, passando por um potencial passivo e se estendendo a um potencial 50 mV acima do potencial de transpassivação. O aço 254 pode ser empregado em substituição à platina em todas as determinações eletroanalíticas realizadas neste trabalho, envolvendo titulações potenciométricas, medidas condutimétricas e determinação de pH. Em medidas de pH em sistemas com força iônica mais baixa, entretanto, é necessário um controle mais adequado do tratamento superficial, além dos realizados neste trabalho, para que a resposta do petencial seja mais rápida. Estes estudos podem contribuir para baixar o custo de análises industriais e de experimentos que venham a ser realizados em laboratórios diáticos. / Special UNS S31254 stainless steel (254 SS), an austenitic stainless steel with 20.1% Cr, 18.4% Ni and 6.42% Mo has been studied in order to be applied in electroanalytical techniques as potentiometry, conductimetry and as a sensor in pH measurements. The electroanalytical studies were preceded of potentiostatic and potentiodynamic polarization curves. The surface characterization was made using FTCIR, SEM and XPS as techniques. The studies have included, for comparison, UNS S 31603 (316 L SS) and UNS S31678 (F 138 SS); the former is commercially employed in a large extension and the latter is applicable in orthopedic implants. The experiments were made at 25° C, beginning with the electrochemical characterization of the ferrous materiais in different aqueous media: chloridric, acetic, sulfuric, nitric and D-galacturonic acids and saline solutions of sodium chloride, sodium sulfate and sodium nitrate, changing the electrolyte concentration. SS 254 is passivated in most of the studied media, on the entire potential range analyzed (from corrosion potential to transpassivation potential). In acetic media it was observed the largest potential range where 254 SS is passivated, indicating that a higher energy is necessary to disrupt the passivant film, due to a higher Mo concentration at the surface, detected using SEM. Pitting corrosion was observed in HCl and NaCl media at potential more positive than Etr. SEM surface characterizations have shown aluminium oxide and calcium oxide inclusions. XPS analyses have indicated the presence of Mo (VI) on the polished surface and that there is a gradual Mo (VI) increasing, in solution, when the potential changes from Ecorr to E > Etr. 254 SS can be used in potentiometric and conductimetric titrations and as a sensor electrode for pH measurements. However, in biological applications a more adequate surface treatment is needed in order to obtain rapid responses. Overall the results suggest that 254 can be used as substitute of platinum in different electroanalytical techniques. This finding contributes to lower the cost of experiments to be performed in didactic laboratories and/or industrial analyses.

Neste trabalho, foram determinadas as propriedades mecânicas de fadiga de baixo e alto ciclo e de tenacidade à fratura JIC de um aço inoxidável austenítico do sistema Cr-Mn-N, utilizado na confecção de colares para perfurações pela indústria de exploração de petróleo. Foi também avaliada a influência da temperatura de serviço nas propriedades mecânicas do aço, que apresentou um decréscimo significativo nos valores dos limites de escoamento e de resistência e do alongamento com o aumento da temperatura. Na temperatura ambiente, os ensaios de fadiga de baixo e alto ciclo foram realizados segundo as normas ASTM E606 e ASTM E466. Em temperaturas superiores, as propriedades de fadiga foram estimadas utilizando alguns métodos atualmente disponíveis, que utilizam somente as propriedades mecânicas de tração. Os resultados obtidos mostraram uma pequena influência da temperatura na vida à fadiga na região de baixo ciclo e uma grande influência na região de alto ciclo. A curva tensão-deformação cíclica do material foi obtida pelo método convencional e pelo método do passo incrementai, que utiliza somente um corpo de prova. Os ensaios de JIC foram realizados nas temperaturas ambiente e 150°C, segundo a norma ASTM E813, utilizando a técnica de variação da flexibilidade elástica. Na temperatura ambiente, foi observada uma grande dispersão nos valores obtidos de JIC, atribuída à presença de uma fase frágil, identificada como precipitados de carbonitretos mistos de ferro, cromo, manganês e nióbio. Foi também observada uma diminuição no valor médio de JIC com o aumento da temperatura. / In the present work, the low and high cycle fatigue and fracture toughness properties of a Cr-Mn-N austenitic stainless steel used for application in drill collars were investigated. Also, the temperarure dependence of the tensile properties was determined, and it was found that the yield strength, ultimate strength and elongation values decrease significantly with the temperature. The low and high cycle fatigue testing were carried out at room temperature according to ASTM E606 and ASTM E466 standards. At high temperarure, the fatigue properties were estimated from monotonic propetties obtained in the tensile testing. The results showed small influence of temperature in the fatigue life in the short-life range and great influence in the long-life range. The cyclic stress-strain curve was obtained by companion specimen tests and incremental step tests methods. The last method showed to be advantageous because only one specimen and short testing time were required. The fracture toughness was detennined at room temperature and at 150°C applying elastic-plastic fracture mechanics concepts. The single specimen elastic compliance technique for crack length determination was employied. At room temperature a great scattering of the JIC values was observed due the presence of the brittle phase identified as a precipitates of carbonitride content Fe, Cr, Mn, Nb elements. Also a decreasing of average value o f the JIC was observed with the increasing of temperature.

Made available in DSpace on 2017-07-21T19:26:06Z (GMT). No. of bitstreams: 1 Bruna Corina Kurelo.pdf: 9097435 bytes, checksum: 9e2ea56fd2dfc2427ab47a5b071d8244 (MD5) Previous issue date: 2013-04-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nitriding by glow discharge (DL) and a new technique called luminous glow discharge with cathodic cage (DLGC) were techniques widely employed today for surface treatment. In the present work were investigated nanoscale tribo-mechanical properties of three grades:austenitic stainless steel (AISI 316), Martensitic (AISI 420) and supermartensitic (HP13Cr) subjected to treatments by DL and DLGC techniques. Martensitic steels have been previously heat-treated in 1025 C (AISI 420) and 1100C (HP13Cr) with subsequent rapid cooling in oil. The three classes of steels have been nitrided using the following parameters of temperature – time : 350 C/6 h, 400 C/6 h e 450 C/6 h (to DL and DLGC). The nitriding treatments were held in atmospheres of N2/H2 in the proportions of 20 %-80 % (in volume) to DL and 80 %-20 % (in volume) to DLGC. For the characterization of the samples were employed the techniques of x-ray diffraction (DRX), scanning electron microscopy (SEM), optical microscopy (OM), atomic force microscopy (AFM) and Energy Dispersive X-ray Spectrometry (EDS). The mechanical properties were evaluated by instrumented indentation (II), and, with the same equipment, the nano scratch tests. In the samples treated by DL the temperature influence the formation of different stages (γN or αN, γ'-Fe4N, ε-Fe2 + xN, CrN). In the treatments carried out at low temperature (350 C) the predominant phase formed is γN to austenitic steel AISI 316 and phases γ' and ε for martensitic steels HP13Cr and AISI 420, due to difference in solubility and diffusivity of nitrogen in the austenite and martensite phases.Nitriding treatments by DL cause the effect of chromium depletion to all steels in the temperature of 450°C. To DLGC treatments occurs the formation of ε phase regardless of temperature. By this way higher temperatures favor the formation of the phases γN and αN. In treatments by DLGC, hardness of the deposited layer measured by II remained, regardless of steel, next to that of the reference sample. The hardness of the modified layers existing below the films produced by DLGC is next the hardness of the layers produced by DL but no border effect and low roughness. In treatments by DL, the hardness increased from 2,5 GPa up to 15,5 GPa for steel AISI 316. The estimated thicknesses of modified surfaces treated by DL are superior to those of the layers deposited and modified by DLGC at same parameters. The scratch resistance of modified surfaces by DL increases to any conditions of treatment. The greatest value of critical load of scratch resistance obtained (126.7 ± 32.1 mN) for the layers deposited by DLGC is too low for typical applications expected of these steels. However, further analyzes are necessary in the modified layer to check the applicability of this technique for these steels.The conditions of excellence found for DL technique can provide an increase in the useful life of the parts treated in the media, where they are employed that require good mechanical and tribological properties. / Dentre as várias técnicas empregadas na atualidade para tratamento de superfícies, destaca-se a nitretação por Descarga Luminosa (DL) e uma nova técnica denominada nitretação iônica por DL com Gaiola Catódica (DLGC). No presente trabalho investiga-se as propriedades tribo-mecânicas em nanoescala de três classes de aços inoxidáveis: austenítico (AISI 316), martensítico (AISI 420) e supermartensítico (HP13Cr) submetidos a tratamentos pelas técnicas de DL e DLGC. Os aços martensíticos foram previamente tratados termicamente em 1025 °C (AISI 420) e 1100 °C (HP13Cr) com posterior resfriamento rápido em óleo. Os três aços foram nitretados nas seguintes condições de temperatura/tempo: 350 °C/6 h, 400 °C/6 h e 450 °C/6 h (DL e DLGC). As nitretações foram realizadas em atmosferas de N2/H2 nas proporções de 20 %-80 % para DL e 80 %-20 % para DLGC. As superfícies foram caracterizadas pelas técnicas de difração de raios X (DRX), microscopia eletrônica de varredura (MEV), microscopia de força atômica (MFA) e espectroscopia de raios X por energia dispersiva (EDS). As propriedades mecânicas foram avaliadas por indentação instrumentada (II), e, com o mesmo equipamento, realizaram-se os ensaios de nanorisco. Na técnica de DL ocorre influência da temperatura de tratamento na formação das diferentes fases (γN ou αN, γ’-Fe4N, ε- Fe2+xN, CrN); nos tratamentos realizados a baixa temperatura (350 °C) predomina a formação da fase γN para o aço austenítico AISI 316 e das fases γ’ e ε para os aços HP13Cr e AISI 420, de estrutura martensítica, devido a diferença de solubilidade e difusividade de nitrogênio nas diferentes fases austenita e martensita. Os tratamentos de nitretação por DL causam o efeito da depleção do cromo em quaisquer dos aços na temperatura de 450 C. Nos tratamentos por DLGC ocorre a formação da fase independentemente da temperatura. Entretanto temperaturas mais altas propiciam a formação das fases γN e αN. Nos tratamentos por DLGC, a dureza da camada depositada medida por II permaneceu, independentemente do aço, próxima à da amostra de eeferência. A dureza das camadas modificadas existentes abaixo dos filmes produzidos por DLGC é próxima a dureza das camadas produzidas por DL mas sem efeito de borda e com baixa rugosidade. Nos tratamentos por DL, a dureza elevou-se de 2,5 GPa a até 15,5 GPa para o aço AISI 316. As espessuras estimadas para as camadas modificadas de amostras tratadas por DL são superiores às das camadas depositadas e modificadas de amostras tratadas por DLGC nos mesmos parâmetros. A resistência ao risco das superfícies modificadas por DL aumenta para quaisquer condições de tratamento. O maior valor de carga crítica de resistência ao risco (126,7 ± 32,1 mN) obtido para as camadas depositadas por DLGC é um valor muito baixo para as aplicações típicas esperadas desses aços. No entanto, são necessárias análises complementares na camada modificada para verificar a aplicabilidade dessa técnica para estes aços. As condições de excelência encontradas para a técnica de DL podem proporcionar um aumento da vida útil das peças tratadas nos meios onde são empregadas que exigem boas propriedades mecânicas e tribológicas.

O fresamento do aço inoxidável austenítico é um processo importante para a produção de peças em que se deseja alta resistência mecânica e à corrosão. No entanto, a usinagem desse material representa um desafio por suas características adversas ao corte. A alta taxa de encruamento e a alta dureza relativa fazem-no resistente ao corte, podendo gerar vibrações em diferentes faixas de frequência. Uma técnica importante ao processamento de sinais de vibração é a Transformada de Wavelet que permite analisar diferentes frequências do sinal através da subdivisão em aproximações e detalhamentos. Neste trabalho analisaram-se vibrações em alta e baixa frequência geradas no fresamento frontal do aço inoxidável austenítico AISI 316 a partir de sinais de força, coletados por meio de um dinamômetro piezelétrico e processados via Transformada de Wavelet Discreta. Também se fez a investigação dos perfis de rugosidade, dos parâmetros de rugosidade média (Ra) e média parcial (Rz) e das ondulações gerados na superfície fresada. Nos ensaios, foram utilizados insertos com três raios de ponta distintos, hastes da fresa com três diferentes comprimentos em balanço e foram variadas a rotação do eixo-árvore e a profundidade de corte axial em três níveis cada, totalizando 81 combinações de parâmetros. Constatou-se que a profundidade de corte representou a maior influência na vibração. Na usinagem com rotações abaixo do valor mínimo recomendado pelo fabricante (1600 rpm), houve dificuldades na formação e remoção do cavaco. A modificação do raio de ponta influenciou mais a vibração em pequenas profundidades de corte ou em zonas próximas às condições de instabilidade. O comprimento da haste mostrou comportamentos diferentes para a vibração, podendo estar relacionado com a mudança das frequências naturais do sistema e também pode definir entrada em regime instável. Verificou-se correlação do detalhamento (D1) da força resultante (vibração em altas frequências) com o parâmetro Ra para condições de vibrações intensas (maiores amplitudes), mas em regime estável. Assim, o parâmetro D1 pode ser utilizado na detecção de vibrações chatter no processo de fresamento frontal do aço inoxidável AISI 316. / The milling of austenitic stainless steel is important process for the production of part that require mechanical and corrosion resistance. However, the machining of this steel represents a challenge by its adverse features. The high hardening rate and the high relative hardness make it resistant to cutting and can generate vibrations in different frequency ranges. An important technique for the processing of vibration signals is the Wavelet Transform that allows the analysis of different signal frequencies through the subdivisions into approximations and details. In this work, high and low frequency vibration generated in end milling of AISI 316 stainless steel were analyzed from force signals collected through a piezoelectric dynamometer and processed via Wavelet Discrete Transform. Besides, the roughness profiles were investigated, as well as average (Ra) and partial mean (Rz) roughness parameters, and waviness generated on the milled surface. Three different insert nose radius, end mill tool lengths, depths of cut and spindle speeds were used in the experiments, totaling 81 combinations of parameters. It was found that depth of cut represented the greatest influence on vibration. In end milling with spindle speed below the minimum recommended by the tool manufacturer (1600 rpm) it occurred difficulties in the chip formation and removal. The modification of tool nose radius greater influenced the vibration at small depths of cut or in regions close to the stability limit. The end mill tool length showed different behaviors for the vibration, which may be related to the change of natural frequencies of the mechanical system and may also define an unstable state. The correlation of detail (D1) of the resulting force (vibration at high frequencies) with the parameter Ra for intense vibration conditions (larger amplitudes) was verified, but in stable state. Thus, D1 can be used for detecting chatter in end milling process of AISI 316 stainless steel.