Global organisation
The long-term strength increase of moist cured concrete is a classic example that cement hydration generally continues for a long time. Two examples: Sivasundaram et al. [9] found that the compressive strength of a fly ash concrete increased 36% between 3 months and 3.5 years, and Ding et al. [10] found similar increases in compressive strength between 1 …
RISE erbjuder möjligheten att med isoterm kalorimetri studera värmeutveckling vid konstanta betingelser. Några områden där metoden kan användas är: nedbrytning och åldring, …
Andra exempel på utskiljningshärdning är karbonitrering av stål, mikrolegering av kolstål, och härdning av olika aluminiumlegeringar. Deformationshärdning Härdningen orsakas av att …
glödgning. För att eliminera spänningen i H13-stålsmidning, förbättra strukturen, förädla kornet, minska hårdheten för bearbetning, glödgning är en nödvändig process, utförs vanligtvis hög temperatur / isotermisk sfäroidiseringsglödgning: 860 ~ 890 ℃, uppvärmning och hållning för 2h, kylning till 740 ~ 760 ℃ isotermisk 4h, ugn kall till cirka 500 ℃ ur ugnen.
: The effect of the parameters of isothermal treatment at low temperatures, also called Austempering, on the impact toughness, hardness and microstructure of AISI 4340 steel was investigated.
The determining significance of isothermal holding on microstructure and mechanical properties of a transformation-induced plasticity steel (Fe-1.67Mn-1.32Al-0.55Si-0.47C) was studied with multiple techniques including x-ray diffraction, scanning electron microscopy and transmission electron microscopy. The objective was to design an optimal …
A physically based process model for the room temperature yield strength of an age-hardenable alloy subject to selected monotonic non-isothermal heat treatment schedules is developed and used to ...
The current study focuses on an industrial hardening process where the steel parts are austempered in a molten salt bath. The aim of the study was to compose a predictive tool for more qualified ...
DMA - Dynamisk Mekanisk Analys DMA - Dynamic Mechanical Analysis DSC - Differentiell Svepkalorimetri DSC - Differential Scanning Calorimetry E c - Entalpi krävande för …
DSC-målinger kan udføres dynamisk ved anvendelse af en lineær temperaturstigning, isotermisk eller med temperaturmodulation. Temperaturscanninger anvendes til at undersøge …
The high-temperature flow behavior and flow stress sensitivity of BT25y alloy were investigated. Results show that hot deformation is accompanied by the dynamic competition between work hardening and flow softening.
• Depending on the specific type of the BBR instrument, tempering the liquid bath takes relatively long (total 60 min, including a stabilization time of 20 min to achieve ± 0.2°C), and ...
The isothermal aging behavior of a cold-rolled precipitation hardening stainless steel has been studied at 723 K (450 °C) for holding times up to 72 hours. The precipitation hardening has been investigated using microhardness Vickers (Hv), thermoelectric power (TEP) measurements, and tensile testing. Microhardness compared to TEP measurements is more …
vid konstant temperatur (isotermisk) från helt austenitiserat tillstånd. Används vid beräkningar av kylning efter uppvärmning för att erhålla önskad struktur i stålet.
For inelastic modeling of polycrystalline materials with small strain, although vigorous multi-scale models have been developed, the economical macroscopic phenomenological models based on continuum mechanics which meet the practical needs of engineering still need further adaptability research and development (Chaboche et al., …
Värmebehandling är en kritisk process för att ge komponenter i metalliska material rätt egenskaper. RISE erbjuder tillämpad forskning, utveckling, utbildning och uppdrag inom …
Abstract A unified viscoplastic constitutive model with wide temperature adaptability is developed based on the basic framework of the Chaboche type model to capture the intricate cyclic viscoplastic behaviors of Haynes 230 subjected to isothermal low-cycle fatigue and fatigue-creep loads. By introducing effective aging time into drag stress in the hyperbolic sine viscosity …
Isoterm betyr at noe har lik eller samme temperatur. En prosess som foregår ved konstant temperatur kalles en isoterm prosess. Den eldste gassloven, Boyle–Mariottes lov, gjelder for en isoterm prosess: Produktet pV er konstant når temperaturen holdes konstant. Her er p gasstrykket og V volumet av en viss mengde gass.
The processing variable which has received the most attention is temperature. The effect of temperature on the precipitation process from supersaturated solid solutions and the resulting hardening effects have been experimentally studied for nearly 100 years [4] the laboratory this is often achieved by monitoring the hardness as a function of isothermal …
Detta är ett arbete gjort på Scania Engine om härdning av vevaxlar till lastbilar som används i kommersiell fordonsindustri. Gällande hållbarhetsaspekter finns det möjligtvis en vinning i att …
provkropparna undersöks med avseende på skillnad i dynamisk elasticitetsmodul samt därefter ett förstörande spräckhållfasthetstest. En noggrannare analys av mikrostrukturen genomförs av …
The study of physics first started in the 17th century. While physics has run the world we live in since before humans existed, the 17th century was when scientists first started trying to understand and name those processes. In the centuries that followed, those studies led to the discovery of countless new and useful processes, including the isothermal process.
Strain rate sensitivity, temperature sensitivity, and strain hardening during the isothermal compression of BT25y alloy Xuemei Yang,a) Hongzhen Guo, and Zekun Yao School of Materials Science and Engineering, Northwestern Polytechnical University, Xi''an 710072, People''s
3 Figure 1: A schematic illustration of the three types of flow curves (i) with steady-state stress value; (ii) with peak stress value; and (iii) with gradually increasing
Structural Project No. WND-POIG.01.01.02-14-100 / 09, 2015r 09 "Manufacturing of nanocrystalline steel using phase transformations" implemented under the Operational Program Innovative Economy,
Aiming at the enhancement of the lightweight potential of press hardening steels, investigations on the formability of thin, boron alloyed, hot dip aluminized steel sheets are carried out. The material formability is described through Forming Limit Diagram (FLD), determined by means of Nakajima formability test of thin 22MnB5 sheets (0.50 mm, 0.80 mm, 1.25 mm) at …
Isoterm kalorimetri, även kallat mikrokalorimetri kan användas för att studera endoterma och exoterma processer. Metoden mäter mycket små energimängder och är därför extra lämplig för …
Behandlingen är en isotermisk process i lägre temperatur än de andra, normalt mellan 500 och 600 grader. Processen ger tunna lager av karbider som skapas med den kemiska …
Hærdning, ændring af materialers egenskaber, så de bliver hårdere eller (for glas) mere modstandsdygtige over for fx stød og slag.
A constitutive, non-isothermal unified hardening (UH) model is presented to interpret the thermo-elasto-plastic behaviours of normally consolidated and overconsolidated clays. Two yield surfaces are adopted in the proposed model: the current yield surface and the reference yield surface. A UH parameter (H) is developed to describe the evolution of the …
Isothermal annealing (Figure 29.15) is conducted by heating the steel within the austenite single-phase region (i.e. above Ac 3 for a hypoeutectoid steel, or above Ac 1 for a eutectoid steel) for a time sufficient to complete the solutionising process, yielding a completely austenitic microstructure. The steel is then cooled rapidly at a specified rate within the pearlite …
Abstract—The possibility of increasing the wear resistance of ductile VCh500-7 iron by isothermal quenching using a new method is studied. It differs in that cooling and holding are carried out according to the water–furnace scheme, not in a molten salt and alkali, as in the current technology. An increased level of wear resistance is achieved by obtaining in the …
In the production of critical parts for various machines and mechanisms, expensive structural steels are used alloyed with chromium, nickel, molybdenum, and vanadium.
Efforts have been made on the steels to improve their toughness. Grain refinement is one of the prevailing methods. Zhang et al. adopted a double-solution treatment to refine the grains, and obtained the maraging steel with excellent cryogenic toughness [17].Calcagnotto et al. designed an ultrafine grained dual-phase (DP) steel by large strain …
Initial precipitation and hardening mechanism during non-isothermal aging in an Al–Mg–Si–Cu 6005A alloy Wenchao Yanga,b,⁎, Shouxun Jib, Lanping Huangc, Xiaofei Shenga, Zhou Lia, Mingpu Wanga aSchool of material Science and Engineering, Central South University, Changsha, 410083, China bBrunel Centre for Advanced Solidification Technology (BCAST), …