Solution Annealing Temperature Research Articles

The Effect of the Solution Annealing Temperature in the Hardening Process on the Properties of Al-Si-Cu Alloys

The Effect of the Solution Annealing Temperature in the Hardening Process on the Properties of Al-Si-Cu Alloys

An investigation of the influence of integration of steel heat treatment and brazing process on the microstructure and performance of vacuum-brazed cemented carbide/steel joints

Cemented carbides are commonly brazed to transformation hardening tool steels without taking a proper and adequate steel heat treatment into account. This publication shows the limits and possibilities of integrating a steel heat treatment, including a quenching process, into a vacuum brazing process. Therefore, copper-based filler metals are selected to ensure the steel component’s high and homogenous hardness and supply a high joint quality. In this context, the aimed steel hardness was chosen in the range between 400 and 440 HV1 based on industrial experiences. This specific hardness range for the steel component was set to avoid wear of machining tools in subsequent machining steps if the steel hardness is too high and to prevent wear and deformation of the tool itself in case of a steel hardness too low. When using the transformation hardening tool steel 1.2344, the obtained shear strength values did not exceed a threshold of 20 MPa which can be attributed to the required N2-quenching from brazing respectively solution annealing temperature. However, the steel components featured a hardness of 527.1 HV1 for the specimens brazed with pure copper at 1100 °C and 494.0 HV1 for those brazed with a CuGeNi filler metal at 1040 °C. This publication also shows an alternative route to manufacture long-lasting tools with a cemented carbide/steel joint by applying the difficult to wet and not well researched, but for many other reasons very suitable precipitation hardening maraging steel. Especially, the comparable low coefficient of thermal expansion (CTE) and the capability of the lath martensite to compensate large amounts of externally imposed stresses during the austenite-to-martensite transformation as well as the cooling rate independent of the hardening mechanism of the maraging steel and a pre-applied nickel coating including the corresponding diffusion processes are responsible for a sound joint with a shear strength > 300 MPa. Moreover, the subsequent tempering process at 580 °C for 3 h provides the maraging steel joining partner with a hardness of 426.6 ± 6.0 HV1.

Effect of Solution Annealing Temperature on the Pitting Response of Niobium-Stabilized Super Duplex Stainless Steel

Effect of Solution Annealing Temperature on the Pitting Response of Niobium-Stabilized Super Duplex Stainless Steel

The Increase of Fracture Toughness with Solution Annealing Temperature in 18Ni Maraging 300 Steel

Abstract Maraging steels are a class of ultra high strength steels of special importance due to their extremely high mechanical strength and good toughness. In this work, the effects of the solution annealing temperature on the mechanical properties of the maraging 300 steels were evaluated, in order to maximize the toughness without considerable detriment of the mechanical strength. Five solution annealing temperatures were evaluated. The characterization of the mechanical properties was done by tests of Rockwell C hardness, Charpy-V impact toughness, and tensile and fracture toughness in plane strain. The results obtained show that the fracture toughness increases, and the tensile strength decreases with the temperature of the solution annealing. In this way it was possible to find a heat treatment condition in which it was possible to raise about 20% of the toughness with a loss of only 6% in the tensile strength.

Study of Sigma Phase in Duplex SAF 2507

Super duplex stainless steel is one of the stainless steel which has a combination between high strength properties and excellent corrosion resistance. However, the resistance can decrease by precipitation of sigma phase which is formed at high temperature, for example after welding processes. A series of experiments has been performed to study the effect of solution annealing to existence of sigma phase on super duplex SAF 2507. Variations of solution-annealing temperatures were 1000 °C, 1065 °C and 1125 °C with holding time of 15 and 30 minutes for each temperature. Effect of solution annealing process was characterized by using XRD, SEM, and Optical Microscopy. The result showed precipitation of sigma phase completely dissolved at 1065 °C and 1125 °C because it reformed to austenite. After it was heated at 1065 °C, chromium carbide appeared in ferrite site and grain boundary. The amount of chromium carbide increased with the increasing of solution annealing temperature.

Influence of Solution Annealing on Microstructure and Mechanical Properties of Maraging 300 Steel

Maraging 300 belongs to a family of metallic materials with extremely high mechanical strength and good toughness. Some works have been published about aging temperatures that improve ultimate strength resistance with acceptable toughness levels in this steel family, where the prior austenite grain size obtained by different solution annealing temperature influence in the final mechanical properties. Solution annealing temperatures ranging from 860 °C to 1150 ºC and were kept constant until the aging temperature. These treatments were used in order to investigate their influence on the microstructure and mechanical properties of maraging steel 300, especially with regard to toughness. The characterization of the microstructure was performed by optical microscopy, scanning electron microscope (SEM) and X-ray diffraction (XRD). Mechanical properties were evaluated by Rockwell C hardness and Charpy impact tests. The results showed that there is a temperature range where one can get some improvement in toughness without a large loss of mechanical strength.

Effect of Solution Annealing Temperature on Pitting Behavior of Duplex Stainless Steel 2204 in Chloride Solutions

The effect of solution annealing temperature ranging from 950 to 1200 °C on the microstructure and corrosion performance of duplex stainless steel (DSS) 2204 were investigated. The proportion of the ferrite phase increased while the austenite phase decreased and the ferrite stabilizing elements diluted in the ferrite phase with the increase of annealing temperature. The critical pitting temperature (CPT) of specimens annealed at 1000 °C was higher than those annealed at 950 °C, whereas further increasing the annealing temperature to 1200 °C decreased the CPT. The pitting initiation sites were observed in the austenite phase, at the boundary of ferrite/austenite phase and inside the ferrite phase for specimens annealed at 950, 1000 °C and exceeding 1100 °C, respectively. The evolution trend of the CPT and the pit initiation site were analyzed by the pitting resistance equivalent number.

Effect of Mean Stress and Solution Annealing Temperature on Ratcheting Behaviour of AISI 304 Stainless Steel

The present investigation has been carried out to understand the effect of mean stress on room temperature ratcheting behaviour of solution annealed AISI 304 stainless steel at constant stress amplitude. It is found that the ratcheting strain to failure linearly increases with increase of mean stress and there is no significant difference in the accumulated ratcheting strain with change in solution annealing temperature vis-a-vis grain size. While the number of cycles to complete failure increases exponentially with mean stress irrespective of solution annealing temperature, the ratcheting life is found to increase when soltionin annealing is done at lower temperature. This variation is believed to be associated with the tensile yield strength of the specimens solutionised at two different temperatures.

Effect of Mn Content and Solution Annealing Temperature on the Corrosion Resistance of Stainless Steel Alloys

The corrosion behavior of two specially designed austenitic stainless steels (SSs) having different Nickel (Ni) and Manganese (Mn) contents was investigated. Prior to electrochemical tests, SS alloys were solution-annealed at two different temperatures, that is, at 1030°C for 2 h and 1050°C for 0.5 h. Potentiodynamic polarization (PD) tests were carried out in chloride and acidic chloride, whereas linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) was performed in 0.5 M NaCl solution at room temperature. SEM/EDS investigations were carried out to study the microstructure and types of inclusions present in these alloys. Experimental results suggested that the alloy with highest Ni content and annealed at 1050°C/0.5 hr has the highest corrosion resistance.

Effects of Solution-Annealing Temperature on the Precipitation of Secondary Phases and the Associated Pitting Corrosion Resistance in Hyper Duplex Stainless Steel

The effects of the solution-annealing temperature on the precipitation of secondary phases and the associated pitting corrosion resistance in hyper duplex stainless steel after aging at 1123K were investigated in a highly concentrated chloride solution. Increasing the solution annealing temperature from 1333 to 1413K retarded the formation of the secondary phases owing to a decrease in both the number of preferential precipitation sites such as the ferrite/austenite interface and the activities of Cr, Mo and W. The slow rate of degradation of the pitting corrosion resistance of the alloy with the increase in the solution annealing temperature appears to be caused by the retardation of the precipitation of the sigma phase. Based on the results of the precipitation of secondary phases and electrochemical tests, the optimal solution annealing temperature was determined to be 1373K. [doi:10.2320/matertrans.M2012402]

Effects of Solution Annealing Temperature on the Galvanic Corrosion Behavior of the Super Duplex Stainless Steels

This study investigated the active dissolution of super duplex stainless steel (SDSS) at various solution annealing temperatures. The active dissolutions of the α-phase and γ-phase were compared, and the effects of the surface area ratio on the active dissolutions of both phases were investigated. There were two peaks in the active-passive transition region in the potentiodynamic test in the modified green-death solution. The two peaks changed as the solution annealing temperature was increased from 1050 to 1150 °C. The solution annealing temperature difference affected the critical anodic current densities. This provides useful information for determining the appropriate solution annealing temperature in the modified green-death solution for SDSS.

A Review of Haynes<sup>®</sup> 230<sup>® </sup>and 617 Alloys for High Temperature Gas Cooled Reactors

HAYNES® 230® and 617 alloys are competing for use on Generation IV, high temperature gas cooled reactor components because of good high temperature creep strength in the temperature range between 760°C and 982°C and resistance to oxidation in the gas cooled reactor environment. A review of the metallurgy affecting the properties in each alloy will be discussed. Grain size and carbide precipitation developed during fabrication effect short term and long term ductility, fatigue, and creep. For example, 230 alloy has a finer grained structure which promotes fatigue strength with a slight sacrifice in creep strength. The 617 alloy has a coarser grain structure which provides slightly higher creep resistance while sacrificing some fatigue strength. Thermal aging also introduces gamma prime precipitation to the 617 alloy as well as grain boundary carbides, and this, in addition to grain boundary oxidation, reduces the low cycle fatigue strength of 617 alloy compared to 230 alloy. Independent studies have shown that 230 alloy possesses higher resistance to thermal fatigue than 617 alloy. However, welds of both base metals with similar weld composition have about the same thermal fatigue life. Cooling rates from solution annealing temperatures during processing effect the ductility and creep strength of these alloys with the highest cooling rates preferred for retention of ductility and creep strength. The reason; slow cooling rates promote carbide precipitation in the grain boundaries which reduces ductility and creep strength.

Stress-reorientation of hydrides and hydride embrittlement of Zr–2.5 wt% Nb pressure tube alloy

Hydrogen in excess of the terminal solid solubility precipitates out as a brittle hydride phase in zirconium alloys. The hydrides acquire platelet shaped morphology due to their accommodation in the matrix and can cause severe embrittlement, especially when these are oriented normal to the tensile stress axis. The precipitation of hydride platelets normal to the tensile stress when cooled under stress from a solution-annealing temperature is commonly referred to as ‘stress-reorientation’. The stress-reorientation is associated with a threshold stress below which no reorientation is observed. In this work, stress-reorientation of hydrides was investigated for unirradiated, cold worked and stress-relieved Zr–2.5 wt% Nb pressure tube material for a reorientation temperature of 423–723 K. The effect of the reoriented hydrides on the tensile properties of the Zr–2.5 wt% Nb pressure tube alloy was evaluated in the temperature range of 298–573 K.

Characterization of solutionizing behavior in VT14 titanium alloy using ultrasonic velocity and attenuation measurements

VT14 titanium alloy (Ti–4.5Al–3Mo–1V) was subjected to a series of heat treatments consisting of solutionizing for 1 h at the selected temperatures in range of 923–1323 K at an interval of 50 K, followed by water quenching. Hardness and optical microscopy results are correlated with ultrasonic longitudinal and shear wave velocities and attenuation in these specimens. Ultrasonic velocities and hardness decrease with solution annealing temperature (SAT) in the 923–1123 K range. Beyond 1123 up to 1223 K, they increase slightly. Beyond 1223 K, ultrasonic velocities become constant, whereas hardness increases up to 1323 K. Ultrasonic attenuation exhibits an opposite behavior to velocity and hardness. Further, for the first time, authors have shown that ultrasonic velocity can be used to identify the β-transus temperature in this alloy. Because of non-monotonous variation of velocity and attenuation with solutionizing temperature, it was not possible to identify the SAT using any one of these parameters. Hence, a new parameter, ratio of normalized differential of ultrasonic attenuation to normalized differential of ultrasonic velocity (RNDAV) has been used, which is found to increase monotonously with SAT and hence enabling unambiguous characterization of SAT in solution annealed VT14 alloy.

Decomposition of Austenite in Austenitic Stainless Steels

Austenitic stainless steels are probably the most important class of corrosion resistant metallic materials. In order to attain their good corrosion properties they rely essentially on two factors: a high chromium content that is responsible for the protective oxide film layer and a high nickel content that is responsible for the steel to remain austenitic. Thus the base composition is normally a Fe-Cr-Ni alloy. In practice the situation is much more complex with several other elements being present, such as, Mo, Mn, C, N among others. In such a complex situation one almost never has a single austenite phase but other phases invariably form. Those phases are, with few exceptions, undesirable and they can be detrimental to the corrosion and mechanical properties. It is therefore of considerable importance to study the formation of such phases. In this work the decomposition of austenite in austenitic stainless steels is reviewed in detail. First the binary equilibrium diagrams relevant to the system Fe-Cr-Ni are briefly presented as well as other diagrams, such as the Schaeffler diagram, that traditionally have been used to predict the phases present in these steels as a function of composition. Secondly the precipitation of carbides and intermetallic phases is presented in detail including nucleation sites and orientation relationships and the influence of several factors such as composition, previous deformation and solution annealing temperature. Next, the occurrence of other constituents such as nitrides, sulfides and borides is discussed. TTT diagrams are also briefly presented. Finally the formation of martensite in these steels is discussed.

Influence of Solution-Treatment Conditions on the Cellular Precipitation in Si-Doped Cu–10Ni–8Sn Alloy

The influence of solution-annealing conditions (temperature and time) on the nucleation and growth of grain boundary cells in the 0.2%Si-doped Cu-10%Ni-8%Sn alloy on aging at 723K was investigated by the quantitative metallographic method. The hardness change in the matrix during aging at 723 K was scarcely affected by the solution-annealing conditions. However, the nucleation and growth of the cell during aging was remarkably affected by the solution-annealing conditions. When the solution-annealing temperature or time was increased, the suppressing effect of Si on the cellular precipitation was decreased

Void nucleation and growth in solution-treated FV548 steel irradiated with 1 MeV electrons

A study has been made of void formation and growth in FV548 steel irradiated with 1 MeV electrons to try to resolve some anomalies in the behaviour of FV548 as compared with 316 steel. In general the results show that the behaviour of FV548 is completely consistent with that of 316 steel; for example the activation energy of the void density is 1.3 eV with no helium and 0.6–0.7 eV with 10 ppm helium in both, and the swelling rate S is a monotonic function of the void density Nv. The S versus Nv curves depend upon the irradiation temperature and the solution-annealing temperature in FV548, but they are not changed by helium injection, cold-working, or cast-to-cast variations.It has been observed that the S versus Nv curves correctly describe the effect of a temperature change, the new S being that predicted by the curve for the appropriate temperature and Nv. The S versus Nv curve has been used to determine the contribution made to void growth by the material as a function of distance from a void.

Fe-Mn-C系オーステナイト合金の機械的性質に及ぼす鋼組成熱,処理条件の影響

Fe-Mn-C系オーステナイト合金の機械的性質に及ぼす鋼組成熱,処理条件の影響