Metallurgical Approach for the Development of Heat Treatment Applied to 316L Stainless Steel Cold Spray Coatings

2021 ◽  
Author(s):  
Laury-Hann Brassart ◽  
Anne-Françoise Gourgues-Lorenzon ◽  
Jacques Besson ◽  
Francesco Delloro ◽  
David Haboussa ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Heat Treatments ◽  
Recrystallization Temperature ◽  
Scanning Calorimetry ◽  
Spray Coatings ◽  
Treatment Conditions ◽  
Long Time ◽  
Temperature Ranges ◽  
Sprayed Coatings

Abstract Industries developing cold-spray processes aim at producing dense and resistant coatings. Controlling microstructure and inter-particular fracture characteristics of sprayed coatings is essential to improve their properties. To do so; post-spraying heat treatment is a promising approach. This work addresses the development of such heat treatments and focuses on the analysis of recovery and recrystallization. Different heat treatment parameters were explored; namely; holding temperature and time; heating rate; and heating method. This approach revealed a competition between recrystallization and other microstructural evolution mechanisms; such as precipitation and porosity coalescence. An optimized heat treatment; allowing microstructural softening and adequate mechanical properties; was sought after. First; differential scanning calorimetry measurements applied to as-sprayed coatings enabled to identify recovery and recrystallization temperature ranges. Then; a variety of heat treatments was applied; involving long-time isothermal holdings as well as shorter cycles. Microstructure analysis and hardness measurements allowed making a first selection of treatment conditions.

Novel Powder Modification Method for the Cold Spray of Hard Steels

2021 ◽  
Author(s):  
D. Poirier ◽  
Y. Thomas ◽  
B. Guerreiro ◽  
M. Martin ◽  
M. Aghasibeig ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Steel Powder ◽  
Deposition Efficiency ◽  
Maximum Temperature ◽  
Powder Size ◽  
H13 Tool Steel ◽  
Treatment Conditions ◽  
Dense Deposits ◽  
Modification Method

Abstract A novel powder modification method based on the simultaneous softening and agglomeration of steel powders via heat treatment in a rotary tube furnace has been investigated as a means to improve the cold sprayability of H13 tool steel powder. By adjusting starting powder size and shape as well as heat treatment conditions (maximum temperature, cooling rate, and atmosphere), cold spray of H13 powder went from virtually no deposition to the production of thick dense deposits with a deposition efficiency of 70%. Powder agglomeration, surface state, microstructure evolution, and softening are identified as key factors determining powder deposition efficiency and resulting deposit microstructure.

scholarly journals Effect of Heat Treatment on Rheological Properties of Bambangan (Mangifera pajang kosterm) Fruit Juice

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Jumardi Roslan ◽  
Hay Chye Ling ◽  
Mohd Dona Sintang ◽  
Suryani Saallah
Keyword(s):  
Heat Treatment ◽  
Rheological Properties ◽  
Fruit Juice ◽  
Market Potential ◽  
Pseudoplastic Fluid ◽  
Treatment Conditions ◽  
High Temperature Short Time ◽  
Long Time ◽  
Mild Temperature ◽  
Short Time

Bambangan (Mangifera pajang Kosterm) is an indigenous fruit that can be found in Borneo Island including Sabah and Sarawak (Malaysia), Kalimantan (Indonesia), and Brunei. Besides being freshly eaten, the pulp of bambangan fruit can be processed for juice production to expand its market potential. During the processing of fruit juice, the application of heat treatment such as pasteurization and sterilization might influence their rheological behavior. Thus, the present study aims to investigate the effect of heat treatment on the rheological properties of bambangan fruit juice (BFJ). The freshly squeezed BFJ was subjected to different heat treatment conditions; sterilization (121°C, 3 minutes), mild temperature long time (MTLT) pasteurization (65°C, 15 minutes), and high temperature short time (HTST) pasteurization (90°C, 1 minute). Rheological analysis of the heat-treated BFJ was performed using a rheometer at a shear rate ranging from 1 to 250 s-1 and a temperature between 5 °C to 70 °C. Pasteurization at 90 °C for 1 minute (HTST) was found to be the most suitable heat treatment for the BFJ. At this condition, the BFJ exhibited a non-Newtonian pseudoplastic fluid behavior (n < 1), fitted well with the Herschel-Bulkey model. The value of parameters obtained from Herschel-Bulkley equation for HTST treatment of bambangan juice were n= 0.83, k= 0.32 and yield stress= 3.96. The viscosity values of HTST bambangan juice at the temperature of 5, 20, 40 and 70 °C were 3.53, 2.33, 1.53 and 1.76 Pa.s respectively. This rheological information is of fundamental importance in optimizing equipment design, process control, and sensory evaluation.

Numerical Simulation of CrMo Steels Thick Welds Intermediate Postweld Heat Treatments

2005 ◽  
Author(s):  
Maryline Clerge´ ◽  
Christian Boucher ◽  
Sylvain Pillot ◽  
Philippe Bourges
Keyword(s):  
Heat Treatment ◽  
Complex Shape ◽  
Heat Treatments ◽  
Pressure Vessels ◽  
Post Weld Heat Treatment ◽  
Treatment Conditions ◽  
Stress Relieving ◽  
Creep Resistant Steels ◽  
Postweld Heat ◽  
Hydrogenation Treatment

During manufacturing, complex shape welded pressure vessels are submitted to numerous intermediate heat treatments after each weld (de-hydrogenation treatment - DHT and/or intermediate stress relieving treatment - ISR) before final Post Weld Heat Treatment (PWHT). The present study aims at analysing and optimising the intermediate heat treatment conditions regarding the resulting mechanical properties (tensile strength and impact. strength) of CrMo and CrMoV creep resistant steels. Hydrogen behaviour in weld metal and HAZ, and residual stresses evolution have been assessed by numerical modelling and experimental measurements on welded specimens representative of big pressure vessels: butt welds and set in nozzle welds of 150 mm wall thickness. The optimised conditions are compared to usual construction codes and buyer’s requirements.

Microstructural Contributions to Stress Corrosion Cracking in High Strength Steels

1982 ◽  
Vol 40 ◽  
pp. 462-463
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Strength Steels ◽  
High Strength ◽  
Heat Treatments ◽  
Corrosion Cracking ◽  
Treatment Conditions ◽  
300M Steel ◽  
Conventional Heat Treatment

The effects of microstructural variables upon stress corrosion cracking resistance of 300M steel in 3.5% NaCl solution have been studied. Table 1 lists KIscc values for three heat treatment conditions. The martensite substructure was predominantly twinned plates for conventional heat treatment and dislocated laths for both high temperature and step heat treatments. A typical twinned region observed in the conventional heat treatment is shown in Fig. 1. Such twinned regions were less frequent in the other heat treatments. Both cementite and epsilon carbide were seen in all cases, as illustrated in Figs. 2 and 3 for conventional heat treatment. Epsilon carbide was usually observed within large grain boundary nucleated laths (autotempered martensite), with definite habit planes and growth directions. The formation of such laths have been discussed previously. Retained austenite, mostly in the form of interlath films, was observed in all cases with increased amounts present in coarser grained structures (Fig. 4).

Cold Spray MCrAlY Coatings on Single-Crystal Ni-Base Superalloys: A Substrate Perspective

2021 ◽  
Author(s):  
Deliang Guo ◽  
Bertrand Jodoin ◽  
Linruo Zhao
Keyword(s):  
Heat Treatment ◽  
Single Crystal ◽  
Cold Spray ◽  
Gas Turbines ◽  
Solution Heat Treatment ◽  
Spray Deposition ◽  
Isothermal Oxidation ◽  
Heat Treatments ◽  
Mcraly Coatings ◽  
Oxidation Performance

Abstract The hot-section components of modern gas turbines (e.g.; turbine blades and vanes) are typically manufactured from Nibase superalloys. To develop the γ/γ' microstructure that imparts superior thermomechanical and creep properties; Nibase superalloys usually require three distinct heat treatments: first a solution heat treatment; followed by primary aging; and finally secondary aging. To achieve oxidation resistance; MCrAlY coatings are applied on the superalloy components as either environmental coatings or bond coats for thermal barrier coatings. In this study; the effects of different processing sequences on MCrAlY coating characteristics and short-term isothermal oxidation performance were investigated. Specifically; cold spray deposition of NiCoCrAlTaY coatings was carried out on single-crystal Ni-base superalloy substrates that underwent various degrees of the full heat treatments prior to being coated. The remaining required heat treatments for the superalloy substrates were then performed on the coated samples after the cold spray deposition. The microstructures of the CMSX-4 substrates and NiCoCrAlTaY coatings were characterized after each heat treatment. Isothermal oxidation performance of the coated samples prepared using different sequences was evaluated at 1100°C for 2 hours. The results suggested a promising procedure of performing only solution heat treatment on the superalloy substrate before coating deposition and then primary aging and secondary aging on the coated samples. This processing sequence could potentially improve the oxidation performance of MCrAlY coatings; as the aging processes can be used to effectively homogenize coating microstructure and promote a thin thermally grown oxide (TGO) scale prior to actual isothermal oxidation.

Effect of Heat Treatment Conditions on Microstructure and Infrared Transmission Property of Germanate Oxyfluoride Glass-Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1285-1288
Author(s):  
Zhuo Hao Xiao ◽  
Sheng Long Wang
Keyword(s):  
Heat Treatment ◽  
Crystal Size ◽  
Structural Characteristics ◽  
Glass Ceramics ◽  
Infrared Transmission ◽  
Oxyfluoride Glass ◽  
Treatment Conditions ◽  
Ir Transmission ◽  
Temperature Ranges ◽  
Good Transparency

Germanate oxyfluoride glass in CaF2/BaF2-AlF3-SiO2-GeO2 was prepared by melt quenching technique and subsequently converted to glass-ceramics with microstructures comprised nano-crystallites in a residual glass matrix by two-step heat treatments process. DSC, XRD, SEM and IR transmission investigations were used to determine structural characteristics and optical property of the prepared germanate oxyfluoride glass-ceramics. The influences of heat treatment conditions on crystallization behaviors and infrared transmission were discussed. The results show that crystal phase in the glass-ceramics is only Ge2Al6O13 and the crystal size is about 20nm-80nm when treated temperature ranges from 900 oC to 960oC. Good transparency is exhibited in visible light band to midinfrared band (5.0um) when treated temperature is low than 940 oC.

Precipitation Behaviour and Mechanical Properties during Short-Term Heat Treatment for Tailor Heat Treated Profiles (THTP) of Aluminium Alloy 6060 T4

2016 ◽  
Vol 877 ◽  
pp. 400-406 ◽  
Author(s):  
Hannes Fröck ◽  
Matthias Graser ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Michael Lechner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloy ◽  
Heat Treatments ◽  
Maximum Temperature ◽  
Short Term ◽  
Scanning Calorimetry ◽  
Heat Treated ◽  
Precipitation Behaviour ◽  
Dissolution And Precipitation

Precipitation hardening aluminium alloys are widely used for automotive applications. To enhance the application of aluminium profiles, improved formability is needed. Tailor Heat Treated Profiles (THTP) with locally different material properties attempt to increase formability e.g. in bending processes. Tailoring of local properties is obtained by a local short-term heat treatment, dissolving the initial precipitate state (retrogression) and still allowing subsequent ageing. In the present study, the dissolution and precipitation behaviour of the aluminium alloy EN AW-6060 T4 was investigated during heating with differential scanning calorimetry (DSC). Heating curves from 20 to 600 °C with heating rates of 0.01 up to 5 K/s were recorded. Interrupted heat treatments with different maximum temperatures were performed in a deformation dilatometer. Immediately afterwards, tensile tests were carried out at room temperature. The course of the recorded mechanical properties as a function of the maximum temperature is discussed with regard to the dissolution and precipitation behaviour during heating. Finally, the aging behaviour of the investigated alloy was recorded after different typical short-term heat treatments and is discussed with reference to the DSC‐curves. The correlation of the microstructure and the mechanical properties enables the derivation of optimal parameters for the development of THTP through a local softening.

scholarly journals Investigation of the films based on the uronate polysaccharides by the method of differential scanning calorimetry

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
N. Коndratjuk ◽  
Ye. Pyvovarov ◽  
Т. Stepanova ◽  
Yu. Matsuk
Keyword(s):  
Heat Treatment ◽  
Differential Scanning Calorimetry ◽  
Calcium Ions ◽  
Total Concentration ◽  
Moisture Loss ◽  
Dynamic Mode ◽  
Scanning Calorimetry ◽  
Ionotropic Gelation ◽  
Complete Disintegration ◽  
Temperature Ranges

In this paper, the problem of studying of the films properties on the basis of uronate polysaccharides (sodium alginate and pectin low-esterified amidated), created on the principle of ionotropic gelation with the participation of calcium ions, has being considered. The purpose of the study is to determine the patterns of films formation based on the composition of the uronate polysaccharides, to determine their properties when heated and conditions of destruction or combustion. The thermophysical properties of the films in the temperature range 20–500°C were controlled by the method of differential scanning calorimetry in the dynamic mode. The temperature at which the loss of external and internal moisture is occurring have been determined. The temperatures when films are subjected to destruction have been founded. Thus, the mass loss of samples was noted in the following temperature ranges: 52–100°С and 40–100°С; the maximum moisture loss was noted at 83 and 85°C for specimens with a total concentration of uronate polysaccharides 2% and 3% respectively. Maximum external moisture losses were 6% and 9%; intra-linked moisture – 28.5 and 29% respectively. Complete disintegration of polymers occurs after 300 and 310°C for specimens with a total concentration of uronate polysaccharides 2% and 3% respectively. The investigation of the destraction temperatures of the above systems allows us to predict the principle of heat treatment of semi-finished products contained in films, created on the basis of the reaction of ionotropic gelation of polysaccharides and calcium ions.

Sign in / Sign up

Export Citation Format

Share Document