Effects of heat treatment on the microstructure and metallurgical properties of the explosively bonded 304 stainless steel—CK45 steel

2016 ◽  
Vol 27 (4) ◽  
pp. 488-506 ◽  
Author(s):  
Mohammadreza Khanzadeh Gharah Shiran ◽  
Seyyed Javad Mohammadi Baygi ◽  
Seyed Rahim Kiahoseyni ◽  
Hamid Bakhtiari ◽  
Mohsen Allah Dadi

In this research, the effects of heat treatment are studied on the microstructure and mechanical properties of the explosive bonding of 304 stainless steel plates and CK45 carbon steel with a constant explosive load and various standoff distances. The samples are heat treated in a furnace for 2-h and 4-h at 250℃ and 350℃. The results imply that by increasing the standoff distance from 4 to 5 mm, the impact kinetic energy increases and severe plastic deformation occurs in the bonding interface. The metallography results indicate the wave-vortex nature of the interface with the increase of standoff distance. In addition, heat treatment for 2 h at 350℃ leads to an increase in the thicknesses of intermetallic compounds in the interface. Also, the hardness decreases from 271 to 171 Vickers, and from 279 to 195 Vickers with 2 h of heat treatment at 350℃ in samples with standoff distances of 4 and 5 mm, respectively. Furthermore, the strengths of the samples decrease from 449 to 371 MPa, and from 510 to 433 MPa, respectively. Hardness and strength changes occur due to changes in the thickness of the intermetallic area and an increase in grain sizes.

1966 ◽  
Vol 88 (1) ◽  
pp. 33-36 ◽  
Author(s):  
F. W. Bennett ◽  
C. P. Dillon

A statistical evaluation has been made of the effect of weld rod composition, ferrite content, and heat-treatment upon the impact strength of certain austenitic stainless-steel welds in 304 stainless-steel plate at −320 F. The data indicate that suitable and approximately equivalent properties are obtained with 310 stainless-steel rod in the as-welded condition, type 308 stainless-steel rod in the as-welded condition (ferrite less than 6 percent), and 308L stainless-steel rod either as-welded or stress-relieved at 1750 F (ferrite less than 9 percent). The impact resistance of 310 stainless steel is adversely affected by stress relief, apparently due to carbide precipitation in this alloy. The 308 and 308L stainless-steel rods are both adversely affected by a stress relief at 1550 F, indicative of sigma formation. The carbon content in 308 stainless-steel rods apparently is not a major factor, as indicated by the lack of adverse effects with a 1750 F stress relief, from which the rate of cooling through the sensitizing range of 800 to 1500 F is identical with that in the 1500 F stress relief. The basic practical conclusion to be drawn from these data is that regular carbon 304 stainless steel welded with 308L stainless-steel rod can be used in cryogenic applications, and that the decision as to whether to stress relieve or not may be left to the mechanical engineer, subject only to the stipulation of a minimum stress-relieving temperature of 1750 F.


2017 ◽  
Vol 873 ◽  
pp. 3-8 ◽  
Author(s):  
Mohamed Ramadan ◽  
Khalid M. Hafez ◽  
K.S. Abdel Halim ◽  
N. Fathy ◽  
Tadachika Chiba ◽  
...  

The present study is undertaken to investigate the influence of annealing and normalizing heat treatment on the bimetallic interface microstructures of 304 stainless steel and gray cast iron. The current work is aim to control the bimetal interface microstructures by different types of heat treatment processes to improve performance of the bimetallic castings performance. For low temperature annealing, specimens are heated to 760 0C for 60 min in an electrical heating furnace. For high temperature annealing and normalizing, specimens are heated to 920 0C for 120 and 240 min. A different interface structures are obained for all heat treated samples. Annealing and normalizing induce a significant effect on the diffusion of C and Cr elements and slightly effect on the diffusion of Ni element. Thickness of interface layer 1 (austenite + carbide) increases by increasingthe annealing temperature.


Author(s):  
Marios Kazasidis ◽  
Elisa Verna ◽  
Shuo Yin ◽  
Rocco Lupoi

AbstractThis study elucidates the performance of cold-sprayed tungsten carbide-nickel coating against solid particle impingement erosion using alumina (corundum) particles. After the coating fabrication, part of the specimens followed two different annealing heat treatment cycles with peak temperatures of 600 °C and 800 °C. The coatings were examined in terms of microstructure in the as-sprayed (AS) and the two heat-treated conditions (HT1, HT2). Subsequently, the erosion tests were carried out using design of experiments with two control factors and two replicate measurements in each case. The effect of the heat treatment on the mass loss of the coatings was investigated at the three levels (AS, HT1, HT2), as well as the impact angle of the erodents (30°, 60°, 90°). Finally, the response surface methodology (RSM) was applied to analyze and optimize the results, building the mathematical models that relate the significant variables and their interactions to the output response (mass loss) for each coating condition. The obtained results demonstrated that erosion minimization was achieved when the coating was heat treated at 600 °C and the angle was 90°.


2011 ◽  
Vol 189-193 ◽  
pp. 3891-3894
Author(s):  
Ya Min Li ◽  
Hong Jun Liu ◽  
Yuan Hao

The casting Fe3Al intermetallics were solidified in sodium silicate sand mould and permanent mould respectively to get different cooling rates. After heat treatment (1000°С/15 h homogenizing annealing + furnace cooling followed by 600°С/1 h tempering + oil quenching), the microstructure and properties of Fe3Al intermetallics were investigated. The results show that the heat-treated Fe3Al intermetallics at higher cooling rate has finer grained microstructure than lower cooling rate, and the lattice distortion increases due to the higher solid solubility of the elements Cr and B at higher cooling rate. The tensile strength and hardness of the Fe3Al intermetallics at higher cooling rate are slightly higher also. However, the impact power of intermetallics at higher cooling rate is 67.5% higher than that at lower cooling rate, and the impact fracture mode is also transformed from intercrystalline fracture at lower cooling rate to intercrystallin+transcrystalline mixed fracture at higher cooling rate.


2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt

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.


2013 ◽  
Vol 795 ◽  
pp. 492-495 ◽  
Author(s):  
Mohd Noor Mazlee ◽  
Alvin Tan Yin Zhen ◽  
Shamsul Baharin Jamaludin ◽  
Nur Farhana Hayazi ◽  
Shaiful Rizam Shamsudin

Tensile shear strength and ageing treatment of dissimilar 6063 aluminum alloy-316L stainless steel joint fabricated by spot welding were investigated. The results showed that tensile shear strength increased with the increasing of welding current. The enhancement of tensile shear strength of the joints was due to the enlargement of the nugget diameter. It was also found that the tensile shear strength values for heat treated joint almost similar to that of non-heat treated joint.


1990 ◽  
Vol 112 (1) ◽  
pp. 116-123 ◽  
Author(s):  
W. J. Mills ◽  
L. D. Blackburn

Heat-to-heat and product-form variations in the JIC fracture toughness for Alloy 718 were characterized at 24, 427, and 538°C using the multiple-specimen JR-curve method. Six different material heats along with three product forms from one of the heats were tested in the modified heat treated condition. This heat treatment was developed at Idaho National Engineering Laboratory to improve the impact toughness for Alloy 718 weldments, but it has also been found to enhance the fracture resistance for the base metal. Statistical analysis of test results revealed four distinguishable JIC levels with mean toughness levels ranging from 87 to 190 kJ/m2 at 24°C. At 538°C, JIC values were 15 to 20 percent lower than room temperature toughness levels. Minimum expected values of JIC (ranging from 72 kJ/m2 at 24°C to 48 kJ/m2 at 538°C) and dJR/da (27 MPa at 24 to 538°C) were established based on tolerance intervals bracketing 90 percent of the lowest JIC and dJR/da populations at a 95 percent confidence level. Metallographic and fractographic examinations were performed to relate key microstructural features and operative fracture mechanisms to macroscopic properties.


2021 ◽  
pp. 307-325
Author(s):  
Jon L. Dossett

Abstract This article introduces some of the general sources of heat treating problems with particular emphasis on problems caused by the actual heat treating process and the significant thermal and transformation stresses within a heat treated part. It addresses the design and material factors that cause a part to fail during heat treatment. The article discusses the problems associated with heating and furnaces, quenching media, quenching stresses, hardenability, tempering, carburizing, carbonitriding, and nitriding as well as potential stainless steel problems and problems associated with nonferrous heat treatments. The processes involved in cold working of certain ferrous and nonferrous alloys are also covered.


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