Influence of Proposed Hardening Process on Hardness and Toughness of Martensitic Stainless Steel

2017 ◽  
Vol 750 ◽  
pp. 103-106
Author(s):  
Charnnarong Saikaew ◽  
Worakarn Sawatwor
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Heat Treating ◽  
Time Range ◽  
Soaking Time ◽  
Heat Treated ◽  
Quench Temperature ◽  
Four Levels ◽  
Level Of Significance ◽  
The Impact

Many researchers have studied the effects of heat treating processes on mechanical properties, corrosion and wear resistance of various martensitic stainless steels. It is crucial to comprehensively understand the role of heat treating processes on the mechanical properties of the steels with a systematic approach. In this work, the specimens were heat treated by preheating in two steps before continuing the heating to the quench temperature. The first preheating was performed in the furnace maintained at 400 °C for 5 min. The second step was done in the furnace kept at 800 °C for 5 min. Then the specimens were heated directly to the hardening temperature, 1030 °C. The specimens reached 1030 °C for a sufficient time of 30 min to form austenite and to allow enough of the carbides to be dissolved to ensure the desired combination of hardness and toughness. After hardening time was over, the specimens were quenched in water to form martensite for 2-8 s and holding in the air for 4 s, followed with water quenching for 2-8 s and cooling to room temperature. Data was collected in order to perform one-way analysis of variance (ANOVA). In this study, the ANOVA consisted of four levels of soaking time of 2, 4, 6 and 8 s and holding time of 4 s. All heat-treated specimens were then used to perform hardness and Charpy-V-Notch impact tests. The results showed that the hardness values increased with increasing of soaking time. The impact energy value slightly decreased with the soaking time range of 2-4 s whereas it rapidly decreased with the soaking time range of 4-6 s and slightly increased with the range of 6-8 s. However, the results from ANOVA showed that the soaking time did not significantly affect the averages hardness and impact energy at the level of significance of 0.05.

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

scholarly journals Microstructure and Mechanical Properties of Heat-Affected Zone of Repeated Welding AISI 304N Austenitic Stainless Steel by Gleeble Simulator

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 773
Author(s):  
Y.H. Guo ◽  
Li Lin ◽  
Donghui Zhang ◽  
Lili Liu ◽  
M.K. Lei
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Energy ◽  
Heat Affected Zone ◽  
Ferrite Content ◽  
Equipment Safety ◽  
Microstructure And Mechanical Properties ◽  
Δ Ferrite ◽  
The Impact

Heat-affected zone (HAZ) of welding joints critical to the equipment safety service are commonly repeatedly welded in industries. Thus, the effects of repeated welding up to six times on the microstructure and mechanical properties of HAZ for AISI 304N austenitic stainless steel specimens were investigated by a Gleeble simulator. The temperature field of HAZ was measured by in situ thermocouples. The as-welded and one to five times repeated welding were assigned as-welded (AW) and repeated welding 1–5 times (RW1–RW5), respectively. The austenitic matrices with the δ-ferrite were observed in all specimens by the metallography. The δ-ferrite content was also determined using magnetic and metallography methods. The δ-ferrite had a lathy structure with a content of 0.69–3.13 vol.%. The austenitic grains were equiaxial with an average size of 41.4–47.3 μm. The ultimate tensile strength (UTS) and yield strength (YS) mainly depended on the δ-ferrite content; otherwise, the impact energy mainly depended on both the austenitic grain size and the δ-ferrite content. The UTS of the RW1–RW3 specimens was above 550 MPa following the American Society of Mechanical Engineers (ASME) standard. The impact energy of all specimens was higher than that in ASME standard at about 56 J. The repeated welding up to three times could still meet the requirements for strength and toughness of welding specifications.

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 Effect of Input Parameter of Cold Isostatic Press (CIP) Towards Properties of Zirconia Block

2019 ◽  
Vol 9 (1) ◽  
pp. 5908-5912
Keyword(s):  
Mechanical Properties ◽  
Wide Spectrum ◽  
Input Parameter ◽  
Strength Properties ◽  
Cold Isostatic Pressing ◽  
X Ray Diffraction ◽  
Cold Isostatic Press ◽  
Forming Process ◽  
Soaking Time ◽  
Four Levels

Zirconia have become widely studied as consequence of their outstanding mechanical properties, such as hardness, mechanical strength and fracture toughness, which allow them to cover a wide spectrum of applications as structural ceramics, including the field of biomaterials. This study was to compare the strength properties of zirconia block with and without Cold Isostatic Press (CIP). The mechanical properties of zirconia block with and without CIP were characterized. Samples of zirconia block will undergo forming process via Cold Isostatic Pressing (CIP), four levels of soaking time (no CIP, 60, 90 and 120 minutes). All of the sample with different soaking time then were sinter in the furnace. The parameter for sintering process was fixed 1300ºC at rate of 3ºC / min. All of the sample were tested for its strength properties using Vickers test. The density and shrinkage of the zirconia block was be analyzed. Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were used to characterize samples if zirconia blocks.

Effect of Tempering Time on Microstructure and Mechanical Properties of SA738 Gr.B Steel

2021 ◽  
Vol 1016 ◽  
pp. 1739-1746
Author(s):  
Yan Mei Li ◽  
Shu Zhan Zhang ◽  
Zai Wei Jiang ◽  
Sheng Yu ◽  
Qi Bin Ye ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Yield Strength ◽  
Microstructure Evolution ◽  
Impact Energy ◽  
Nuclear Power ◽  
Microstructure And Mechanical Properties ◽  
The Impact ◽  
Tempering Time

The effect of tempering time on the microstructure and mechanical properties of SA738 Gr.B nuclear power steel was studied using SEM, TEM and thermodynamic software, and its precipitation and microstructure evolution during tempering were clarified. The results showed that SA738 Gr.B nuclear power steel has better comprehensive mechanical properties after tempering at 650 °C for 1h. With the extension of the tempering time, M3C transformed into M23C6 with increasing size, which affected the yield strength and impact energy. When the tempering time is 8h ~ 10h, due to the transformation of M3C to M23C6, the composition of matrix around the carbide changed, causing the temperature of Ac1 dropped, forming twin-martensite which deteriorated the impact toughness of the steel.

Predicting the Impact of Quenching on Mechanical Properties of Complex-Shaped Aluminum Alloy Parts

1995 ◽  
Vol 117 (2) ◽  
pp. 479-488 ◽  
Author(s):  
D. D. Hall ◽  
I. Mudawar
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Aluminum Alloy ◽  
Boundary Conditions ◽  
Finite Element Program ◽  
Part Geometry ◽  
Heat Treated ◽  
Element Program ◽  
Nozzle Configuration ◽  
The Impact

The mechanical properties of age-hardenable aluminum alloy extrusions are critically dependent on the rate at which the part is cooled (quenched) after the forming operation. The present study continues the development of an intelligent spray quenching system, which selects the optimal nozzle configuration based on part geometry and composition such that the magnitude and uniformity of hardness (or yield strength) is maximized while residual stresses are minimized. The quenching of a complex-shaped part with multiple, overlapping sprays was successfully modeled using spray heat transfer correlations as boundary conditions within a finite element program. The hardness distribution of the heat-treated part was accurately predicted using the quench factor technique; that is, the metallurgical transformations that occur within the part were linked to the cooling history predicted by the finite element program. This study represents the first successful attempt at systematically predicting the mechanical properties of a quenched metallic part from knowledge of only the spray boundary conditions.

scholarly journals Degradation of Roller-Compacted Concrete Subjected to Freeze-Thaw Cycles and Immersion in Potassium Acetate Solution

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Wuman Zhang ◽  
Jingsong Zhang ◽  
Shuhang Chen ◽  
Sheng Gong
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Compressive Strength ◽  
Impact Energy ◽  
Impact Test ◽  
Potassium Acetate ◽  
Acetate Solution ◽  
Freeze Thaw ◽  
Roller Compacted Concrete ◽  
The Impact

Two sets of roller-compacted concrete (RCC) samples cured for 28 days were subjected to freeze-thaw (F-T) cycles and immersion in laboratory conditions. F-T cycles in water and water-potassium acetate solution (50% by weight) were carried out and followed by the flexural impact test. The weight loss, the dynamic elastic modulus (Ed), the mechanical properties, and the residual strain of RCC were measured. The impact energy was calculated based on the final number of the impact test. The results show that the effect of F-T cycles in KAc solution on the weight loss and Ed of RCC is slight. Ed, the compressive strength, and the flexural strength of RCC with 250 F-T cycles in KAc solution decrease by 3.8%, 23%, and 36%, respectively. The content (by weight) of K+ at the same depth of RCC specimens increases with the increase of F-T cycles. The impact energy of RCC specimens subjected to 250 F-T cycles in KAc solution decreases by nearly 30%. Microcracks occur and increase with the increase of F-T cycles in KAc solution. The compressive strength of RCC immersed in KAc solution decreases by 18.8% and 32.8% after 6 and 12 months. More attention should be paid to using KAc in practical engineering because both the freeze-thaw cycles and the complete immersion in KAc solution damage the mechanical properties of RCC.

BRAKE DIE

Alloy Digest ◽  
1976 ◽  
Vol 25 (6) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Heat Treating ◽  
Good Service ◽  
Bethlehem Steel Corporation ◽  
Heat Treated ◽  
Alloy Tool ◽  
Quenching And Tempering ◽  
Steel Heat

Abstract BRAKE DIE is a medium-alloy tool steel heat treated at the mill by oil-quenching and tempering to develop the best combination of properties. It is used for all types of dies on hand-operated and mechanically operated press brakes for the forming and bending of sheets, strip and other flat-rolled metallic and nonmetallic materials. It also will give good service in any application requiring wear resistance, toughness, high mechanical properties and good machinability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: TS-302. Producer or source: Bethlehem Steel Corporation.

TEXTURE AND FORMABILITY DEVELOPMENT OF ASYMMETRY ROLLED AA 3003 AL ALLOY SHEET

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5895-5900 ◽  
Author(s):  
INSOO KIM ◽  
SAIDMUROD AKRAMOV ◽  
HAE BONG JEONG
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Strain ◽  
Research Work ◽  
Heat Treating ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Fine Grain ◽  
Heat Treated ◽  
Crystallographic Orientations

The physical, mechanical properties and formability of sheet metal depend on preferred crystallographic orientations (texture). In this research work, we investigated texture development and formability of AA 3003 aluminum alloy sheets after asymmetry rolling and subsequent heat treatment. After asymmetry rolling, the specimens showed fine grain size. We also investigated the change of the plastic strain ratios after asymmetry rolling and subsequent heat-treating condition. The plastic strain ratios of asymmetrically rolled and subsequent heat treated samples are 1.5 times higher than the initial AA 3003 Al alloy sheets. These could be attributed to the formation of ND//<111> texture component through asymmetry rolling in Al sheet.

Impacted of Vacuum Bag Woven Kenaf/Fiberglass Hybrid Composite

2014 ◽  
Vol 660 ◽  
pp. 572-577
Author(s):  
Syarifah Yunus ◽  
Z. Salleh ◽  
M.A. Aznan ◽  
M.N. Berhan ◽  
A. Kalam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Advanced Technology ◽  
Damage Area ◽  
Bending Stresses ◽  
Post Impact ◽  
The Impact ◽  
Woven Kenaf

This paper discusses the mechanical properties of woven kenaf/fiberglass hybrid composites which has been fabricating using vacuum bag technique. Kenaf fiber had chosen among others natural fibres due to its excellent mechanical properties and potential natural raw fiber to replace plastic or tobacco in manufacturing a multitude of products for the construction, automotive, textile and advanced technology sectors. This study investigates post impact tensile of kenaf hybrid composites and its surface fractured. The impact energy used consists of 4J, 6J, 8J, 12J and 16J. The specimens were clamped between two plate rings with an internal hole diameter of 18mm and impacted with hemispherical nose impactor shape with diameter size of 12.7mm. The results revealed that this kenaf hybrid composite showed significant decreasing of strength and modulus as increasing the impact energy. The damage area affected with fiber fracture occurred much later in fracture process due to high bending stresses.

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