Influence Of Cryogenic Treatment Research Articles

Influence of cryogenic treatment and tempering temperature on microstructural evolution and dry sliding wear behavior of AISI D3 cold-work tool steel

Abstract AISI D3 cold work steel was shallow and deep cryogenically treated and double tempered at 150, 250, and 350 °C temperatures. Cryogenic processes transformed the retained austenite into martensite, while double tempering produced Fe, Cr, and W-rich carbides. The wear losses of cryogenically treated specimens decreased by up to 60% compared to conventionally heat-treated samples. Worn surfaces mainly experienced abrasive and adhesive wear mechanisms. Due to the formation of homogeneously dispersed fine carbides at 250 °C, oxidative wear occurred at the matrix phase, resulting in the lowest wear rate. The samples tempered at 150 °C suffered from the severe abrasive action of hard carbide particles, while the samples treated at 350 °C failed because of carbide coarsening.

Influence of Cryogenic Treatment on the Corrosion Properties of 42CrMo Low Alloy Steel.

In this paper, the effect of deep cryogenic treatment on the corrosion resistance of 42CrMo low alloy steel is investigated and compared with conventional heat-treated counterparts. The low-temperature treatments of the cryogenic process are -120 °C, -160 °C, and -190 °C, respectively. Electrochemical corrosion tests show that the self-corrosion current density of -120 °C, -160 °C and -190 deep-cooled specimens is reduced by 38%, 20% and 30% respectively compared to the usual heat-treated specimens. Scanning electron microscope analysis shows that the precipitation of fine carbides on the surface of the samples treated at -120 °C has improved their corrosion resistance. Electrochemical impedance spectroscopy also shows that the samples treated with -120 °C cryogenic treatment have the smallest corrosion tendency. At a -160 °C deep-cooling process, the precipitated carbide aggregation limits the corrosion resistance of the material. The corrosion resistance of the samples in the -190 °C process group is between the two. The simulation results also express a similar trend to the electrochemical corrosion results.

Effect mechanism of cryogenic treatment on ferroalloy and nonferrous alloy and their weldments: A review

As a different step from conventional heat treatment, cryogenic treatment played a very important role in improving the microstructure and properties of metals. The effect mechanism of cryogenic treatment on steel and non-ferrous metals and their weldments was reviewed. The influence parameters of cryogenic treatment were discussed, and the influence of cryogenic treatment on microstructure was analyzed, which led to the change of tensile strength, corrosion resistance, fatigue resistance, wear resistance and other properties. In addition, the relationship between cryogenic treatment and heat treatment were also discussed. On this basis, the influence mechanism of cryogenic treatment on metal materials was explained from the three aspects of crystal defect, phase transformation and precipitated phase, and the reasons for these phenomena were more deeply understood after cryogenic treatment. On the basis of cryogenic treatment, the method combining with conventional heat treatment and surface treatment was put forward, which provided a new way for obtaining high performance materials. It could be widely used in metal forming and other fields, and provide a broader vision for material post-processing through the prediction of numerical simulation.

Microstructural transformation analysis of cryogenic treated conical rock cutting bits for mining applications

Enhancing the performance of rock cutting bit is an important aspect in reducing mining cost. To enhance their cutting characteristics, rock cutting bits are exposed to different heat treatment techniques. In this research work, an attempt has been made to strengthen the wear resistance of rock cutting bits through sub-zero heat treatment process called cryogenic treatment. The influence of cryogenic treatment (−196 °C) with different soaking duration (6, 12, 18, 24, 30, 36 h) on the microstructure of tungsten carbide (WC-Co) rock cutting bits is investigated through FESEM with the treatment mechanism being elucidated. Hardness of treated and untreated bits was measured using Vickers micro-hardness tester and the variation of crystal phases was examined through X-ray diffraction studies. Rate of bit wear was observed by performing wear studies through pin on disc tribo-meter with different load (5, 10, 15 N) and sliding speed (1, 1.5, 2 m/s). The results showcased the increase in bit hardness, microstructure transformation of martensitic phase (fcc α-Co to hcp ε-Co), hard η carbide formation (Co3W3C, Co6W6C) and enhanced wear rate for treated bit as compared to untreated bit. From the results, it was revealed that CT 24 treated bit possessed highest hardness (1078 HV) and nominal wear rate (87.50%) than UT and other CT bits under 15 N load at 2 m/s.

The influence of cryogenic treatment on titanium alloys mechanical properties

One of the most promising applications of cryogenic therapy is its ability to transform a wide range of materials. In this study, Titanium alloy (Ti6Al4V) was subjected to both deep and shallow cryogenic treatment. In addition to the anti-aging treatment, a deep cryogenic treatment was administered to the patient. Tensile tests were used to examine how cryogenic treatment affected the mechanical characteristics and ductility of Ti6Al4 alloy. According to this studies, cryogenic treatment expands flexibility of Ti6Al4V alloy. After 24 and 36 h, the deep cryo-treated samples had Uniform Plastic Deformation Region (UPDR) that were 5.3% and 8.3% greater than the untreated ones. However, after 36 h of cryogenic treatment, the yield strength of the material decreased by 2%. When subjected to a 36-hour period of severe cryogenic treatment, the alloy's phase ratio decreased from 8.1% to 5.6%, resulting in structural changes within the material. The unstable a phase gave rise to both stable and unstable phases. Experiments have shown that cryogenic treatment raises the flexibility and durability of Ti6AI4V alloy while also controlling the microstructure and lowering residual stress when performed at room temperature.

Influence of Cryogenic Treatment on Tungsten Carbide Cutting Tool Inserts in Improving Resistance to Flank Wear in Machining C-45 Steel

Influence of Cryogenic Treatment on Tungsten Carbide Cutting Tool Inserts in Improving Resistance to Flank Wear in Machining C-45 Steel

Influence of cryogenic treatment on hardness, tensile properties, and microstructure of aluminum alloy AA6061

In this study, an investigation is completed to know the influence of cryogenic thermal therapy on hardness, tensile properties, and microstructural changes of AA6061. The cryogenic thermal treatment is a subsequent process to the conventional heat treatment process in material processing technology. The cryogenic treatment is achieved on samples at (-196 °C) for twenty-four hours in a vessel occupied by liquid nitrogen. Results showed a significant increasing in Vickers micro-hardness values, tensile strength, and yield stress. Also, results explained the precipitation of Magnesium Silicide (Mg2Si) compound clearly in microstructure of alloy samples by light microscopy and scanning electron microscopy.

Influence of cryogenic treatment on tool life, flank wear and surface roughness for machining nickel based super alloy-Haynes 282

With the growing need for hard alloys components and metals, cryogenic machining has gained popularity and Cryogenic machining is seen as a more environmentally friendly feasible and option to flood cooling. This experimentation describes a long-term cryogenic machining solution that takes into account not just traditional machining performance, but also total sustainability performance in each of the three sustainability elements: economy, environment, and society. Haynes 282 alloy was machined under three conditions such as flood lubrication, cryogenic condition and dry condition. It was observed that cryogenic condition was useful for achieving better surface finish of 0.632 µm. In addition to this, less cutting force was required for all cutting speed under cryogenic machining which consumes less power consumption. Tool life decreases with an increase in cutting speed. Maximum tool life of 41.3 min was observed for cryogenic cutting condition at 125 m/min. Higher Flank wear was noticed for flood lubrication condition than cryogenic condition.

The influence of cryogenic treatment and subsequent annealing steps on the structural and phase state of 12Cr18Ni10Ti steel

The paper considers the effect of cryogenic treatment and subsequent annealing steps on structural, corrosion-resistant 12Cr18Ni10Ti steel. The microstructure of steel was studied and the reverse alpha-gamma transformation after cryogenic treatment and additional annealing was revealed. X-ray structural analysis the steel was carried out. As a result of dimpersed analysis in the structure of 12Cr18Ni10Ti steel large particle TiC, etching pits, high sulfur particle were found. Annealing led to the reverse alpha-gamma transformation. The formation of a grain recrystallized structure was found. An increase in the grain size after cryogenic treatment with a subsequent increase in the annealing temperature was recorded 12Cr18Ni10Ti steel.

Influence of Cryogenic Treatment on Microstructure and Mechanical Properties of Ti6Al4V Alloy

Cryogenic treatment is an emerging application that can make significant changes in many materials. In this study, shallow (− 80 °C) and deep (− 196 °C) cryogenic treatment was applied to Ti6Al4V alloy. Additionally, aging treatment and supplementary deep cryogenic treatment were also performed. Tensile tests were done to observe the effects of cryogenic treatment on the mechanical properties and formability of Ti6Al4 alloy. According to the results of these tests, it was observed that the cryogenic treatment had a positive influence on the plasticity properties of Ti6Al4V alloy. For the 24-h and 36-h deep cryo-treated samples, the uniform plastic deformation region (UPDR) was extended 5 and 8.3% compared to untreated sample, respectively. However, this improvement in plasticity observed in samples treated with cryogenic treatment for 36 h led to a decrease in yield strength by 2%. Microstructural and XRD analysis was performed to characterize the microstructural changes that happened with the effect of applied heat treatments. The characterization study shows that with the application of cryogenic treatment internal structure of the material changed, the β phase ratio of the alloy decreased from 8.1 to 5.6% with 36-h deep cryogenic treatment. The unstable β phase was transformed into α phase and stable β phase. The experimental study shows that cryogenic treatment improves the plasticity and toughness of Ti6Al4V alloy at room temperature and regulates the microstructure and reduces the residual stress.

Effect of heat and cryogenic treatment on wear and toughness of HSS AISI M2

Despite the promising results obtained with cryogenic treatment of tool steels, there are still contradictions regarding its benefits, and there is no consensus regarding its mechanisms in the steel microstructure. The goal of this work is to investigate the optimum heat treatment process parameters together with the cryogenic treatment. Samples of AISI M2 steel were austenitized at 1170, 1200 or 1230°C and quenched in salt bath. The cryogenic treatment was performed through nitrogen nebulization with a cooling/heating rate of 0.3°C/min, 24-h holding time at −190°C, before, after or between the double tempering. The influence of cryogenic treatment in AISI M2 steel was dependent on the previous austenitization temperature. No significant reduction in retained austenite was observed by deep cryogenic treatment. The benefits achieved in the resistance to abrasive wear and toughness are associated with lower amount of carbon in the martensite together with finer and more homogeneous carbide precipitation.

Influence of Cryogenic Treatment and Thermal Shock on Quenching Stresses and Properties of Alloy D16

This paper presents the results of heat treatment influence, including quenching in water, cooling of the alloy in liquid nitrogen, holding in it and thermal shock (heating in hot mineral oil) and also natural or artificial aging on the properties of wrought aluminum alloy D16 (2024). With the help of the hole-drilling strain-gage method the influence of heat treatment on residual stresses was determined and using tensile and indentation tests – specific elongation, reduction of area, yield strength, tensile strength and cracking resistance of alloy D16 (2024) were determined. Corrosion properties were studied with potentiodynamic method in 3% aqueous NaCl solution

Influence of cryogenic treatment on mechanical performance of friction stir Al-Zn-Cu alloy weldments

Al-Zn-Cu alloy Al7050-T7451 is used extensively in the aero-space industries. Aerospace components are generally joined using riveting, which increases the overall weight of aeroplane. In this context, friction stir welding (FSW) process could be a potential solution. In this research work, Al7050-T7451 specimens were welded by FSW, using different parametric combinations of tool rotation and welding speed. The friction-stir weldments were further subjected to deep cryogenic treatment. Microstructure and some mechanical properties of the weldments were investigated for both cryo-treated and untreated conditions. It was observed that the grain size of the nugget zone (NZ) got refined after the cryogenic treatment. It was also revealed that microhardness was more in case of cryo-treated joints as compared to untreated. Micro-hardness of the NZ was observed to be highest due to formation of finer grains after exposure to cryogenic temperature. Deep cryogenic treatment has also improved impact toughness and tensile properties such as yield strength and % elongation of the FSW joints.

Influence of cryogenic treatment on the performance of micro-EDM tool electrode in machining of magnesium alloy AZ31B

Abstract Magnesium is one of the elements found in human bone. Therefore, biomedical implants made up of magnesium result in good biocompatibility inside the human body. Magnesium AZ31B being light in weight coupled with good mechanical characteristics can be used as an implant material. The surface integrity of an implant plays an important role in terms of its biocompatibility and stimulating the healing process. Micro-electrical discharge machining (micro-EDM) can be used to achieve the desired surface integrity of implant materials without altering the biocompatibility characteristic. The present study investigates the performance of the untreated and cryogenically treated micro-EDM tool electrodes during machining of magnesium alloy AZ31B. The cryogenic treatment of the tool electrodes was carried out to improve the mechanical properties such as hardness, wear resistance, etc. of the tool electrode which subsequently results in better quality of the machined features. The results showed a significant improvement in the machining performance by the cryogenically treated tool electrode as compared to the untreated tool electrode during micro-EDM of magnesium alloy AZ31B.

Influence of cryogenic treatment on the corrosion of AZ91 and AM60 magnesium alloys in an isotonic solution

Abstract Biodegradable stents made of magnesium alloys have become revolutionary in the cardiovascular area. However, rapid corrosion in a body fluid environment is harmful to the mechanical properties and stability. In this study, untreated and cryogenically treated samples of AZ91 and AM60 alloy were employed at −196 °C for 48 h. Afterwards, the corrosion performance of the AZ91 and AM60 samples was tested in an isotonic solution containing 0.9 wt.-% NaCl. Electrochemical methods such as open-circuit potential measurement (OCP), potentiodynamic polarization, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion performance. In general, the results obtained for the electrochemical studies show that the cryogenically treated AZ91 and AM60 samples maintain superior corrosion resistance when compared to the former sample. The OCP results indicated that the cryogenically treated AZ91 and AM60 outperformed untreated samples after 1 h. The potentiodynamic studies confirmed that cryogenically treated AZ91 and AM60 had superior anodic pitting potential (Epit) and that the passivation zone is higher than AZ91 and AM60 when untreated. The EIS confirmed the lower corrosion kinetics for AZ91 and AM60 treated in the former sample.

Influence of Cryogenic Treatment on the Tribological Behaviour of AISI H21 Tool Steel

The aim of the present work was to find out the optimum cryosoaking duration of deep cryogenic treatment to reduce the wear rate. The AISI H21 hot work tool steel specimens were hardened at 1195 oC, cryotreated at -185 oC for 6 to 30 h, double tempered at 540 oC and soft tempered at 100 oC. The hardness, impact toughness, wear rate and microstructural characteristics of the cryotreated specimens were studied. Wear test parameters were optimized by using Taguchi technique. Analysis of variance and signal to noise ratio were carried out in order to find significant parameters affecting the dependent parameter. The results show that load is the most influencing parameter followed by sliding velocity and cryosoaking duration. The linear mathematical model has been developed for wear rate using a regression analysis technique which will be useful for predicting results for new experiments.

Influence of cryogenic treatment on micro-structural characteristics of some Indian spices: X-ray micro-tomography investigation

Spices are ground cryogenically to retain their thermo-sensitive flavoring compounds, thereby producing a high-quality powder. In the cryogenic grinding process, spices are initially precooled with a cryogen (Liquid nitrogen; LN2) followed by grinding. To simulate and model breakage, fluid, and heat transport phenomena during cryo-grinding an insight of spices micro-structure is required. Thus, the article aims to investigate the effect of cryogenic treatment on micro-structural characteristics of some Indian spices namely black pepper, cinnamon, king chili, and fenugreek. X-ray micro-computed tomography (X-ray μCT) coupled with image analysis was used to observe quantitative parameters along with two- and three-dimensional images of micro-structure of the spices. Dimensional details, color, moisture level, and volatile oil content of the samples were also elaborated in line. The micro-structural changes of cryogenically treated (LN2 dipped) spices were compared with respect to their untreated counterparts. In the treated samples, total pore volume (except for king chili), total sample volume, and total solid volume were relatively higher by 100–526.83%, 5.83–120.90%, and 4.41–120.12%, respectively, along with prominent size distribution of pores. This increase in micro-structural properties of spices has resulted in 2.31–10.45% higher volatile oil extraction yield. Three-dimensional images of micro-structure also supported the inference drawn from the quantitative results. Concurrently, the results confirm the applicability of X-ray μCT as a useful tool to observe micro-structural changes in spices.

Enhancing Wear Resistance of Cryo Treated Cu-Be2 Alloy

In this investigation, the influence of cryogenic treatment on the tribological properties of Cu-Be2 alloy was investigated. Deep cryogenic treatment and shallow cryogenic treatment were applied to Cu-Be2 alloy. As-received (AR), shallow cryogenic treated (SCT) and deep cryogenic treated (DCT) Cu-Be2 alloy were used as pin material. AISI 4140 alloy steel hardened to 513 HV was used as disc. Wear test was carried out using pin-on-disc wear test set-up and the wear tracks were examined using Scanning Electron Microscope. Wear rate and coefficient of friction of the cryogenic treated sample were lower than that of the as-received sample. Adhesive wear, plastic deformation and delamination of asperities were found to be the principal mechanism in the wear characteristics on the as-received as well as the cryogenic treated samples.

Influence of deep cryogenic treatment on viscous behavior of TiC nanopowder/water nanofluid

This paper presents the influence of cryogenic treatment on viscosity of Titanium carbide (TiC)/Water nanofluid. Deep cryogenic treatment is a cooling treatment at −196 °C for 24 h, which is applied to TiC nanopowder. The viscosity is measured for both the TiC/water nano fluid and deep cryogenically treated TiC/water nanofluid. The deep cryogenically treated TiC / Water nano fluid viscosity shows low viscosity when compared to conventional TiC/water nano fluid. The homogenous distribution of TiC nanopowder is responsible for decreasing the viscosity. However, no significant changes are observed in the crystallite size of TiC and Cryo-TiC nano powder from XRD analysis. Scanning Electron Microscope analysis is also done on TiC nano powder and Cryo-TiC nano powder. The homogenous distribution of TiC nano powder is shown in the analysis due to deep cryogenic treatment.

Influence of Tertiary Carbides on Improving Fatigue Limit of H13 Die Steels

Forging dies are subjected to fatigue failures for which different surface treatments are used as most of the failures begin from the surface. In this work, the influence of cryogenic treatment on fatigue limit of die steels has been discussed with hardening of fatigue specimens of AISI H13 die steels at 1020 °C, oil quenching, double tempering at 500 °C, cryogenic treatment at minus 185 °C for 16 h followed by soft tempering at 100 °C. The fatigue limit analysis had been carried out with constant amplitude rotating bending fatigue testing at room temperature, at 3000 rpm with load variations which indicated improved fatigue limit for 16 h cryogenically treated specimens in the high cycle fatigue regime. This has been attributed to decreased surface roughness, increased hardness and precipitation of finer tertiary carbides as an influence of microstructure. The minimum value of fatigue strength exponent, in Basquin equation, has also depicted the increased fatigue limit for cryogenically treated H13 specimens.