scholarly journals Microstructure Evolution and Mechanical Properties of X6CrNiMoVNb11-2 Stainless Steel after Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5243
Author(s):  
Jia Fu ◽  
Chaoqi Xia
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Impact Toughness ◽  
Martensite Phase ◽  
High Density ◽  
Air Cooling ◽  
Rocket Engines ◽  
Forming Process ◽  
The Impact

X6CrNiMoVNb11-2 supermartensitic stainless steel, a special type of stainless steel, is commonly used in the production of gas turbine discs in liquid rocket engines and compressor disks in aero engines. By optimizing the parameters of the heat-treatment process, its mechanical properties are specially adjusted to meet the performance requirement in that particular practical application during the advanced composite casting-rolling forming process. The relationship between the microstructure and mechanical properties after quenching from 1040 °C and tempering at 300–670 °C was studied, where the yield strength, tensile strength, elongation and impact toughness under different cooling conditions are obtained by means of mechanical property tests. A certain amount of high-density nanophase precipitation is found in the martensite phase transformation through the heat treatment involved in the quenching and tempering processes, where M23C6 carbides are dispersed in lamellar martensite, with the close-packed Ni3Mo and Ni3Nb phases of high-density co-lattice nanocrystalline precipitation created during the tempering process. The ideal process parameters are to quench at 1040 °C in an oil-cooling medium and to temper at 650 °C by air-cooling; final hardness is averaged about 313 HV, with an elongation of 17.9%, the cross-area reduction ratio is 52%, and the impact toughness is about 65 J, respectively. Moreover, the tempered hardness equation, considering various tempering temperatures, is precisely fitted. This investigation helps us to better understand the strengthening mechanism and performance controlling scheme of martensite stainless steel during the cast-rolling forming process in future applications.

Application of Tailored Heat Treated Blanks under Quasi Series Conditions

2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Local Heat ◽  
Strength Distribution ◽  
Process Window ◽  
Short Term ◽  
Forming Process ◽  
Heat Treated ◽  
Set Up ◽  
The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

scholarly journals Austenite Reversion Tempering-Annealing of 4 wt.% Manganese Steels for Automotive Forging Application

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 575 ◽  
Author(s):  
Alexander Gramlich ◽  
Robin Emmrich ◽  
Wolfgang Bleck
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Impact Toughness ◽  
Temperature Control ◽  
Annealing Process ◽  
Air Cooling ◽  
Metastable Austenite ◽  
Quenching And Tempering ◽  
Manganese Steels

New medium Mn steels for forged components, in combination with a new heat treatment, are presented. This new annealing process implies air-cooling after forging and austenite reversion tempering (AC + ART). This leads to energy saving compared to other heat treatments, like quenching and tempering (Q + T) or quenching and partitioning (Q + P). Furthermore, the temperature control of AC + ART is easy, which increases the applicability to forged products with large diameters. Laboratory melts distinguished by Ti, B, Mo contents have been casted and consecutively forged into semi-finished products. Mechanical properties and microstructure have been characterized for the AC and the AC + ART states. The as forged-state shows YS from 900 MPa to 1000 MPa, UTS from 1350 MPa to 1500 MPa and impact toughness from 15 J to 25 J. Through the formation of nanostructured retained metastable austenite an increase in impact toughness was achieved with values from 80 J to 100 J dependent on the chemical composition.

Investigation of Heat Treatment on Mechanical Properties of SAE4320 and SAE8620 Alloys

2013 ◽  
Vol 834-836 ◽  
pp. 816-819 ◽  
Author(s):  
Li Jun Tan ◽  
Jun Qiao Wang ◽  
Qing Qun Wang ◽  
Xin Long Chen ◽  
Si Zhu Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Toughness ◽  
Deformation Property ◽  
New Product ◽  
Heat Treatments ◽  
Impact Properties ◽  
The Impact

The tensile and impact properties of SAE4320 and SAE8620 alloys were investigated. Various heat treatments were applied to these two alloys, including different pre-heat treatment. The results shown that after Carburizing and Quenching, both SAE4320 and SAE8620 alloys were highly sensitively to V-notches for their impact samples. In any case, SAE4320 alloy revealed higher tensile strength, better impact toughness and deformation property. Previous work shown that after Carburizing and Quenching, the impact toughness of SAE8620 alloy was too low, the products made of it was very dangerous. Based on the results, a new advanced product was made of SAE4320 alloy instead of SAE8620 alloy. And the new product exhibited good properties. The impact value of the new product far exceeded the older products.

scholarly journals The Effects of Various Conditions of Short-Term Rejuvenation Heat Treatment on Room-Temperature Mechanical Properties of Thermally Aged P92 Boiler Steel

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6076
Author(s):  
Ladislav Falat ◽  
Lucia Čiripová ◽  
Viera Homolová ◽  
Miroslav Džupon ◽  
Róbert Džunda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Room Temperature ◽  
Laves Phase ◽  
Short Term ◽  
Boiler Steel ◽  
P92 Steel ◽  
The Impact

In this work, the effects of various conditions of short-term rejuvenation heat treatment on room-temperature mechanical properties of long-term aged P92 boiler steel were investigated. Normalized and tempered P92 steel pipe was thermally exposed at 600 °C for time durations up to 5000 h in order to simulate high-temperature material degradation, as also occurring in service conditions. Thus, thermally embrittled material states of P92 steel were prepared, showing tempered martensitic microstructures with coarsened secondary phase precipitates of Cr23C6-based carbides and Fe2W-based Laves phase. Compared with the initial normalized and tempered material condition, thermally aged materials exhibited a slight decrease in strength properties (i.e., yield stress and ultimate tensile strength) and deformation properties (i.e., total elongation and reduction of area). The hardness values were almost unaffected, whereas the impact toughness values showed a steep decrease after long-term ageing. An idea for designing the rejuvenation heat treatments for restoration of impact toughness was based on tuning the material properties by short-term annealing effects at various selected temperatures somewhat above the long-term ageing temperature of P92 material. Specifically, the proposed heat treatments were performed within the temperature range between 680 °C and 740 °C, employing variable heating up and cooling down conditions. It was revealed that short-term annealing at 740 °C for 1 h with subsequent rapid cooling into water represents the most efficient rejuvenation heat treatment procedure of thermally aged P92 steel for full restoration of impact toughness up to original values of normalized and tempered material state. Microstructural observations clearly indicated partial dissolution of the Laves phase precipitates to be the crucial phenomenon that played a key role in restoring the impact toughness.

Influence of Mn and Heat Treatment Technology on Microstructure and Mechanical Properties of a Low-Alloy Wear-Resistant Cast Steel Shovel Tooth

2012 ◽  
Vol 557-559 ◽  
pp. 34-37
Author(s):  
Jing Qiang Zhang ◽  
Jie Min Du ◽  
Ji Wei Guo ◽  
Shou Fan Rong ◽  
Guang Zhou Wang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Cast Steel ◽  
Treatment Technology ◽  
Wear Resistant ◽  
Heat Treatment Technology ◽  
Microstructure And Mechanical Properties ◽  
Mn Content ◽  
The Impact

The influences of Mn and heat-treatment technology on microstructure and mechanical properties of medium-carbon-low-alloy wear-resistant cast steel were investigated. The results show that the hardness first increases and then drops down with the increase of Mn content, and the best hardness is 54HRC with Mn content 1.5%. The impact toughness first increases and then drops down with the increase of Mn content. The hardness and impact toughness first increase and then drop down with the increases of quenching temperature. The optimal impact toughness can be obtaind by quenching at 920°C and tempering at 200°C. Part of lower bainite and residual austenite and mass of tempered martensite are obtaind after tempering.

scholarly journals Microstructure Evolution and Mechanical Properties of 0.4C-Si-Mn-Cr Steel during High Temperature Deformation

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 172 ◽  
Author(s):  
Fei Zhang ◽  
Yang Yang ◽  
Quan Shan ◽  
Zulai Li ◽  
Jinfeng Bi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Impact Toughness ◽  
Microstructure Evolution ◽  
Cast Steel ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Grain Sizes ◽  
The Impact

Herein, the effects of height-diameter ratios (H/D) on the microstructure evolution and mechanical properties of 0.4C-Si-Mn-Cr steel during high temperature deformation are reported. The compression experiments were performed on steel samples using Gleeble to obtain a reasonable deformation temperature, and the degree of deformation was assessed in the range of 1.5 to 2.0 H/D via forging. The forged specimens were quenched using the same heat treatment process. The hardness and impact toughness of the steel samples were tested before and after heat treatment. Grain sizes gradually increased with an increase in the compression temperature from 950 °C to 1150 °C, and the grain sizes decreased with an increase in H/D. The microstructure of the steel samples contained pearlite, bainite, martensite, and retained austenite phase. The microstructure after forging was more uniform and finer as compared to that of as-cast steel samples. The hardness and impact toughness of the steel samples were evaluated after forging; hardness first increased and then decreased with an increase in H/D, while the impact toughness continuously increased with an increase in H/D. Hence, the microstructure and properties of steel could be improved via high temperature deformation, and this was primarily related to grain refinement.

Effect of Heat Treatment on the Properties of Inconel X-750

2005 ◽  
Vol 297-300 ◽  
pp. 1220-1222
Author(s):  
Shi Chang Cheng ◽  
Zhao Jie Lin ◽  
Gang Yang ◽  
Zheng Dong Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Impact Toughness ◽  
Room Temperature ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Air Cooling ◽  
Solid Solution Treatment ◽  
Different Temperatures

The authors experimentally investigated the change of mechanical properties of Inconel X-750 alloy under various heat treatments. For the selected specimens, solid solution treatment under different temperatures was carried out, followed air cooling or furnace cooling. Results show that suitable solid solution treatment and air cooling enhances the strength, plasticity, impact toughness at room temperature of the alloy and lowers the hardness of the alloy at room temperature.

Effect of Static Aging on Mechanical Properties of an 18Cr-8Ni-W-Nb-V-N Stainless Steel

2012 ◽  
Vol 706-709 ◽  
pp. 2211-2216
Author(s):  
Ilya Nikulin ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Early Stage ◽  
Secondary Phase ◽  
Fracture Mechanisms ◽  
Aged Condition ◽  
The Impact

The interrelations between microstructure, precipitation and mechanical properties of the 18Cr-8Ni-W-Nb-V-N austenitic stainless steel were examined under long-term aging at 650°C. It was shown that aging leads to decreasing strength characteristics with increasing aging time despite the fact that hardness tends to increase. In none-aged condition the present steel exhibits superior impact toughness of about 255 J/cm-2. This values decreases gradually at the early stage of the aging. After 1000 hours exposure the impact toughness is 195 J/cm-2 and decreases sharply to 135 J/cm-2 at 3000 hours. However, an evidence for ductile fracture was found even after long-term aging. Degradation in impact toughness and mechanical properties with aging is discussed in relation to microstructure evolution, precipitations of the secondary phase and fracture mechanisms.

Effect of Heat Treatment on Impact Toughness of Selective Laser Melted Stainless Steel Parts

2018 ◽  
Author(s):  
Sagar Sarkar ◽  
Soumya Dubey ◽  
Ashish Kumar Nath
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Impact Toughness ◽  
Thermal Loading ◽  
Processing Technique ◽  
Layer By Layer ◽  
Solution Annealing ◽  
Tem Analysis ◽  
Suitable Heat Treatment

One of the versatile additive manufacturing processes is laser based Selective Laser Melting (SLM) which allows to build complex intricate shapes directly from its three dimensional digital images. Layer by layer deposition and depending upon build orientations, SLM parts tends to be anisotropic in nature. Also non-uniformity in thermal loading across the part leads to inhomogeneous microstructure which may have detrimental effect on various mechanical properties. Heat treatment of as-built SLM parts could be used as a post processing technique to reduce the anisotropy and produce homogenous microstructure to ensure reproducible mechanical properties. Application oriented mechanical properties can be obtained for precipitation hardened stainless steel by suitable heat treatment process. Present study is based on effect of heat treatments namely solution annealing, ageing and overaging on impact toughness of SLM 15-5 PH stainless steel. In order to support experimental observations, various metallurgical techniques have been applied. Effect of notch orientations causes anisotropy in impact toughness but this anisotropy is reduced with application of suitable heat treatment. In case of ageing, Transmission Electron Microscopy (TEM) analysis shows formation of fine spherical Cu precipitates which solution strengthens but makes the specimen brittle. As a result relatively lower impact toughness is obtained as compared to overaged condition where combined effect of coarsening of Cu precipitates and increased retained austenite makes the specimen ductile. Increased ageing temperature and soaking time does not have significant effect on impact toughness. However, solution annealing before ageing is recommended for homogenous precipitation throughout the specimen and statistically less scattered data. In all the cases SLM specimens have lower impact toughness to that of cold rolled 15-5 PH stainless steel. Present study could be used as a guideline to get application oriented mechanical properties mainly impact toughness.

EFFECT OF HEAT TREATMENT AFTER WELDING ON THE IMPACT TOUGHNESS OF ASTM A890/A890M SUPERDUPLEX STAINLESS STEEL

2019 ◽  
Author(s):  
Clélia Ribeiro de Oliveira ◽  
Eloá Lopes Maia ◽  
Solange Tamara Fonseca ◽  
Marcelo Martins ◽  
Julian Arnaldo Avila Diaz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Impact Toughness ◽  
Superduplex Stainless Steel ◽  
The Impact
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