The superduplex stainless steels (SDSS) are widely used in chemical, oil and gas industries, to pipelines storage material facilities. In welding process or working temperature elevated, secondary phases may appear the form of precipitates, as sigma phase (σ) which is an intermetallic compound. This compound harmful properties steel, deteriorating its mechanical properties, such decreasing corrosion resistance toughness. this paper it analyzed formation, kinetics microstructural evolution...

Duplex Stainless Steels (DSS) and Superduplex (SDSS) have a strong appeal in the petrochemical industry. These steels excellent properties, such as corrosion resistance good toughness besides weldability. Welding techniques take into account loss of alloying elements during process, so this is usually compensated by addition filler metal rich elements. A possible problem would be welding these materials adverse conditions service, where operator could difficulties with metal. Therefore,...

Duplex stainless steels (DSS) and superduplex (SDSS) are important classes of steels, because they combine the benefits austenite ferrite phases. This results in with better mechanical properties higher corrosion resistance. Owing to these characteristics, DSS SDSS widely employed industry. However, appearance undesirable intermetallic phases their microstructure impairs SDSS. Among phases, main one is sigma phase (σ), which can be nucleated when steel exposed temperature range between 650...

Austenitic stainless steels (ASS) are among the most used structural materials because of their excellent mechanical and corrosive properties. In addition, 316L ASS has weldability its low carbon content. This steel normally contains 5–10% residual delta ferrite to avoid hot cracking micro-fissuring weld metal. Many studies show that selective dissolution austenite or can occur in steel. a survey phases duplex (DSS), Lo coauthors studied effect electrolyte composition (H 2 SO 4 + HCl...

Precipitation of the intermetallic phases embrittles duplex stainless steels. Currently, most studies in this subject simulated aging phenomena by first holding material at different isothermal conditions and then, quenching down under high cooling rates to investigate subsequent microstructures mechanical properties. In work, specimens steel UNS S31803 were submitted cycles controlled non-isothermal conditions. The volume fraction sigma chi formed was less than 1%. value lower that assumed...

Grain boundary pinning by particles is widely used to prevent grain growth during heat treatment in a variety of commercial alloys. Its practical relevance matched considerable amount theoretical work that has been devoted this problem. A key issue the particle/interface interaction mechanism and its associated force. According Ashby et al. an interface may interact with particle two ways: either it goes through or, more usually, bends round envelopes particle. Based on these mechanisms one...

Hydrogen embrittlement can occur when atomic hydrogen is absorbed by steel during the acid cleaning process. In literature, studies of corrosion inhibition organic compounds in solutions have not given attention to permeation steel. this work, we show that best does always indicate inhibition. For first time, imidazole-based were studied as inhibitors carbon pickling hydrochloric at high concentration (5.4 mol L−1). The immersion containing 250 mg L−1 1-butyl-3-methylimidazolium...

A comparison between the Zn-Ni, Zn-Ni-Fe and Zn-Ni-Co coatings was performed in this study. The co-deposition process obtained by electrodeposition on ASTM A624 steel using sulphate baths acid media low current density. characterization of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES), Energy Dispersive (EDS), X-ray diffraction (XRD) Anodic Linear Sweep Voltammetry (ALSV) allowed a detailed analysis phases formed its amounts coatings, which enabled to verify influence Fe...

The properties of the super duplex stainless steels (SDSS) are strongly affected by thermal history imposed welding procedures. controlled dual phase microstructure (ferrite and austenite) guarantee excellent mechanical such as strength corrosion resistance, in addition to small expansion coefficient high conductivity. In this paper, we newly proposed a model able predict pieces coupled with local developed during procedure that combine effects temperature changes welding. We applied inverse...

Structural health monitoring (SHM) is emerging as an essential tool for constant of safety-critical engineering components. Ultrasonic guided waves stand out because their ability to propagate over long distances and they can offer good estimates location, severity, type damage. The unique properties the fundamental shear horizontal wave (SH0) mode have recently generated great interest among SHM community. aim this paper demonstrate feasibility omnidirectional SH0 in a thin aluminum plate...

Samples of the Al 7075 naturally and artificially aged were processed by conventional asymmetrical rolling with 5% thickness reduction. The processes evaluated under room temperature warm condition (130°C). Mechanical properties uniaxial tensile Vickers microhardness tests. Microstructure evolutions followed optical microscopy analysis. Naturally samples showed better yield strengthening processing. Greater ultimate stress ductility processing was also noticed in specimens. Artificially...

There are many studies on austenitic stainless steels with transformation induced plasticity (TRIP). Basically, in these steels, there is a significant increase strength and toughness the of austenite to martensite. 304L steel finds extensive application industry. Studies relating martensitic plastic deformation quite common. Many involve monotonic loading martensite formed. In practice, subject distinct types possibly stress concentrators. Thus, also smaller quantities, it possible find...

Metastable austenitic stainless steels are prone to strain-induced martensite transformation (SIMT) during deformation at room temperature, as in the case of sheet metal forming processes. The SIMT is influenced by chemical composition, grain size, mode or stress state and strain-rate. In this work, interrupted continuous uniaxial tensile tests were performed AISI 304L evaluate a function strain strain-rate effects. was evaluated feritscope temperature in-situ measurements both XRD optical...

In the present work, martensite formation during heat treatment of 1026 steel was studied in order to acquire process knowledge and reinforce effectiveness infrared thermography method evaluate temperature distributions. Several tests were carried out monitored by an camera thermocouples. Martensite fraction evaluated with aid Koistinen-Marburger model adequate parameters describing phase transformations obtained for samples. This research revealed need adjustment accurately describe...

Abstract: Chitosan spherical scaffolds, derived from the deacetylation of chitin, are natural polymers with significant potential, though challenges remain in optimizing their properties. The use chitosan as a carrier for controlled release iron chloride is not yet fully established, despite iron’s critical role various essential biological processes, including component metalloenzymes and maintenance life. Methods: This study aimed to develop novel protocol synthesing scaffolds...

Austempered ductile cast irons (ADI) have received great attention in last years because their combined properties of good ductility, high strength and fracture toughness, fatigue strength, wear low production cost. Such combination can be reached microstructures consist a mixture acicular ferrite (bainite), residual austenite with carbon content nodular graphite. In this work, the effect austempering heat treatment on microstructure commercial alloy to produce three different grades ADI,...

The self-reducing agglomerates produced from powders generated within the electric arc furnace and LD converters is of special interest in process recycling due to amount iron other metals high economical value. However, reducibility inner pore structures play important role on processing technology these materials. Aiming at investigating influence agglomerate structure, some two-dimensional metallographic techniques have been used evaluate porosity clusters with inaccurate results,...

The recrystallization of an electron beam melted Ta-10wt%W alloy deformed by cold swaging with reductions in area 41 and 95% annealed between 1300 oC 1700 is quantitatively described. recrystallized volume fraction the interface per unit are measured. From these quantities microstructural path analyzed. Based on available measurements nucleation growth this discussed. kinetic analysis difficult case due to large initial grain size specimens.

Austempered Ductile Iron (ADI) has excellent mechanical properties related to its microstructure ausferrite, and with the cycle of austempering heat treatment, many can be obtained from same alloy, simply changing time temperature. To evaluate influence temperature on ADI, analyzed modifications in microstructures samples ductile iron, subjected treatment austenitizing 910 °C 90 minutes during bath, were submitted different temperatures, 300, 320, 340, 360 e 380 °C, for four times each...