scholarly journals Evaluation of Effectiveness of Heat Treatments in Boron Steel by Laser Thermography

2021 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Giuseppe Dell’Avvocato ◽  
Davide Palumbo ◽  
Maria Emanuela Palmieri ◽  
Umberto Galietti
Keyword(s):  
Heat Treatment ◽  
Surface Modification ◽  
Heat Treatments ◽  
Boron Steel ◽  
Active Thermography ◽  
Heat Treated ◽  
Surface Laser ◽  
Boron Steels ◽  
Non Destructive

The applicability of active thermography as a non-destructive method to distinguish heat treated from not-treated boron steel has been investigated. While the usual hardness semi-destructive tests influence the inspected surface, laser thermography is capable of verifying the effectiveness of heat treatment in boron steel in a non-destructive way without any surface modification. The procedure has been verified on two plates of boron steels with different structures (100% ferritic–pearlitic and 100% martensitic).

Effect of selective laser heat treatment on geometrical variation in boron steel components: An experimental investigation

2020 ◽  
Vol 235 (1-2) ◽  
pp. 54-64
Author(s):  
Vaishak Ramesh Sagar ◽  
Kristina Wärmefjord ◽  
Rikard Söderberg
Keyword(s):  
Heat Treatment ◽  
High Strength ◽  
Boron Steel ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
Heat Treated ◽  
Geometrical Variation ◽  
And Performance ◽  
Boron Steels ◽  
Heating Direction

Selective laser heat treatment is a well-known process for its ability to produce tailor heat treated blanks (THTB). Specifically, ultra high strength boron steels with tailored material properties can be produced. However, this process generates unwanted distortion and influences geometrical variation. This in turn can affect functionality, aesthetics, and performance of the final product. Understanding the effects on geometrical variation in the final product or the assembly will enable in designing and producing geometry assured products. In this paper, boron steel blanks were selectively laser heat treated with a specific heat treatment pattern and laser heating direction sequence. These heat treated blanks were then cold formed. Further on, spot welding simulation of the cold formed parts was performed to assess the effect on geometrical variation at the assembly level. The results show that the effect of selective laser heat treatment on geometrical variation at part level propagates further to the assembly level. It implies that the effect on geometrical variation should be minimized at part level, when the blanks are laser heat treated. Hence, the sources that influence geometrical variation at part level when employing selective laser heat treatment are presented and discussed. The motivation and possibilities to minimize the effects in the early design concept stages is provided.

Flexural Performance of the Heat-Treated Boron Alloyed Steel

2017 ◽  
Vol 909 ◽  
pp. 21-26
Author(s):  
R. Hafsham ◽  
M.S. Salwani ◽  
H. Mas-Ayu ◽  
Rosdi Daud
Keyword(s):  
Heat Treatment ◽  
Hot Stamping ◽  
Treatment Result ◽  
Boron Steel ◽  
Flexural Test ◽  
Flexural Performance ◽  
Heat Treated ◽  
Quenching Process ◽  
Result Show ◽  
Boron Steels

Boron alloyed steels, especially 22MnB5, have been the point of focus for the materials choice in hot stamping. Objective of this project is to analyze the effect of heat treatment on its flexural performance. In this paper, five conditions of boron steels are analyzed. Specimens consist of the as-received (A), hot pressed (H) and quenched boron steel (QA,QWR, QWC). Flexural test was conducted to give more evidence on the flexural strength of the boron steel based on their process of heat treatment. Result show that Boron steel 22MnB5 undergone quenching process by using water at room temperature yield highest flexural strain.

scholarly journals Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties

2021 ◽  
Author(s):  
Giuseppe Del Guercio ◽  
Manuela Galati ◽  
Abdollah Saboori
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Industrial Applications ◽  
Heat Treatments ◽  
Layer By Layer ◽  
Lattice Structures ◽  
Heat Treated ◽  
Aided Design

Abstract Additive Manufacturing processes are considered advanced manufacturing methods. It would be possible to produce complex shape components from a Computer-Aided Design model in a layer-by-layer manner. Lattice structures as one of the complex geometries could attract lots of attention for both medical and industrial applications. In these structures, besides cell size and cell type, the microstructure of lattice structures can play a key role in these structures' mechanical performance. On the other hand, heat treatment has a significant influence on the mechanical properties of the material. Therefore, in this work, the effect of the heat treatments on the microstructure and mechanical behaviour of Ti-6Al-4V lattice structures manufactured by EBM was analyzed. The main mechanical properties were compared with the Ashby and Gibson model. It is very interesting to notice that a more homogeneous failure mode was found for the heat-treated samples. The structures' relative density was the main factor influencing their mechanical performance of the heat-treated samples. It is also found that the heat treatments were able to preserve the stiffness and the compressive strength of the lattice structures. Besides, an increment of both the elongation at failure and the absorbed energy was obtained after the heat treatments. Microstructure analysis of the heat-treated samples confirms the increment of ductility of the heat-treated samples with respect to the as-built one.

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

GENETICAL STUDIES ON MUTANTS IN THE PROGENY OF HEAT-TREATED BARLEY

1937 ◽  
Vol 15c (5) ◽  
pp. 217-229 ◽  
Author(s):  
F. H. Peto
Keyword(s):  
Heat Treatment ◽  
Mutation Rate ◽  
Heat Treatments ◽  
Plastid Mutation ◽  
Heat Treated ◽  
Natural Mutation

Heat treatments were applied to barley seeds and 10 different mutant characters were observed in the progeny, viz.; xantha1 and 2, dwarf1,2,3 and 4, virescent1 and 2, chlorina and albino. Typical Mendelian ratios were not obtained in the first segregating generation owing to the small size of the sector affected in the generation of treatment. In the second and third segregating generations, good fits were obtained in all cases to either monohybrid or dihybrid ratios. Both 3:1 and 15:1 ratios were observed in lines segregating for xantha1 and albino characters. The postulation of the duplicate factor hypothesis was necessary to explain this situation. Chlorina and dwarf mutants segregated in all the cases investigated as simple Mendelian recessives. One virescent strain was believed to have arisen through plastid mutation and was maternally inherited.The heat treatment significantly increased the natural mutation rate for the xantha characters but apparently had no effect on the albino mutation rate. Dwarf, virescent and chlorina mutants were observed in the segregating generation after heat treatment, but were not detected in untreated populations.

Subpasteurization Heat Treatment to Inactivate Lipase and Control Bacterial Growth in Raw Milk

1982 ◽  
Vol 45 (6) ◽  
pp. 513-515 ◽  
Author(s):  
G. F. SENYK ◽  
R. R. ZALL ◽  
W. F. SHIPE
Keyword(s):  
Heat Treatment ◽  
Lipase Activity ◽  
Raw Milk ◽  
Heat Treatments ◽  
Plate Count ◽  
Psychrotrophic Bacteria ◽  
Standard Plate Count ◽  
Heat Treated ◽  
Standard Plate ◽  
And Control

Raw milk was heat-treated under subpasteurization and suprapasteurization conditions, cooled and stored for up to 72 h at 4.4 and 6.7°C. Milk lipase activity and bacteria counts were monitored in both unheated and heated milks. Inhibition of milk lipase activity ranged from 42 to 98% for treatments of 57.2°C for 10 sec to 73.9°C for 10 sec, respectively. The logs of Standard Plate Count after 72 h of storage at 6.7°C were 6.56, 4.86, 4.31, 4.00 and 2.82 for unheated and 10-sec heat treatments at 57.2, 65.6, 73.9 and 82.2°C, respectively. Psychrotrophic Bacteria Counts were also lower in the heated milks than in the unheated milk. The logs of Psychrotrophic Bacteria Counts after 72 h of storage at 6.7°C were 6.21, 2.45, 2.27, 1.33 and 1.00 for unheated and 10-sec heat treatments at 57.2, 65.6, 73.9 and 82.2°C, respectively. Heat treatment of raw milk supplies would result in limiting action of the milk lipase system and growth of bacteria.

Problems Associated with Heat Treated Parts

2021 ◽  
pp. 307-325
Author(s):  
Jon L. Dossett
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Cold Working ◽  
Heat Treating ◽  
Heat Treatments ◽  
Quenching Media ◽  
Heat Treated ◽  
Nonferrous Alloys

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.

Failure analysis of heat treated HSLA wheel bolt steels

2010 ◽  
Vol 6 (3) ◽  
pp. 373-382
Author(s):  
Ali Nazari ◽  
Shadi Riahi
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Failure Analysis ◽  
Heat Treating ◽  
Boron Steel ◽  
Content Type ◽  
Heat Treated ◽  
Before And After ◽  
Molybdenum Steel ◽  
Optimum Heat

PurposeThe aims of this study is to analyze failure of two types of high‐strength low‐alloy (HSLA) steels which are used in wheel bolts 10.9 grade, boron steel and chromium‐molybdenum steel, before and after heat treatment.Design/methodology/approachThe optimum heat treatment to obtain the best tensile behavior was determined and Charpy impact and Rockwell hardness tests were performed on the two steel types before and after the optimum heat treating.FindingsFractographic studies show a ductile fracture for heat‐treated boron steel while indicate a semi‐brittle fracture for heat‐treated chromium‐molybdenum steel. Formation of a small boron carbide amount during heat treating of boron steel results in increment the bolt's tensile strength while the ductility did not changed significantly. In the other hand, formation of chromium and molybdenum carbides during heat treating of chromium‐molybdenum steel increased the bolt's tensile strength with a considerable reduction in the final ductility.Originality/valueThis paper evaluates failure analysis of HSLA wheel bolt steels and compares their microstructure before and after the loading regime.

scholarly journals Evaluation of Heat-Treated AISI 316 Stainless Steel in Solar Furnaces to Be Used as Possible Implant Material

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 581
Author(s):  
Ioan Milosan ◽  
Monica Florescu ◽  
Daniel Cristea ◽  
Ionelia Voiculescu ◽  
Mihai Alin Pop ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Solar Energy ◽  
Heat Treatments ◽  
Solar Furnace ◽  
316 Stainless Steel ◽  
Heat Treated ◽  
Aisi 316 Stainless Steel ◽  
Aisi 316

The appropriate selection of implant materials is very important for the long-term success of the implants. A modified composition of AISI 316 stainless steel was treated using solar energy in a vertical axis solar furnace and it was subjected to a hyper-hardening treatment at a 1050 °C austenitizing temperature with a rapid cooling in cold water followed by three variants of tempering (150, 250, and 350 °C). After the heat treatment, the samples were analyzed in terms of hardness, microstructure (performed by scanning electron microscopy), and corrosion resistance. The electrochemical measurements were performed by potentiodynamic and electrochemical impedance spectroscopy in liquids that simulate biological fluids (NaCl 0.9% and Ringer’s solution). Different corrosion behaviors according to the heat treatment type have been observed and a passivation layer has formed on some of the heat-treated samples. The samples, heat-treated by immersion quenching, exhibit a significantly improved pitting corrosion resistance. The subsequent heat treatments, like tempering at 350 °C after quenching, also promote low corrosion rates. The heat treatments performed using solar energy applied on stainless steel can lead to good corrosion behavior and can be recommended as unconventional thermal processing of biocompatible materials.

scholarly journals Short Heat Treatments for the F357 Aluminum Alloy Processed by Laser Powder Bed Fusion

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6157
Author(s):  
Matteo Vanzetti ◽  
Enrico Virgillito ◽  
Alberta Aversa ◽  
Diego Manfredi ◽  
Federica Bondioli ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Precipitation Hardening ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Point Of View ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Heat Treated ◽  
Direct Aging

Conventionally processed precipitation hardening aluminum alloys are generally treated with T6 heat treatments which are time-consuming and generally optimized for conventionally processed microstructures. Alternatively, parts produced by laser powder bed fusion (L-PBF) are characterized by unique microstructures made of very fine and metastable phases. These peculiar features require specifically optimized heat treatments. This work evaluates the effects of a short T6 heat treatment on L-PBF AlSi7Mg samples. The samples underwent a solution step of 15 min at 540 °C followed by water quenching and subsequently by an artificial aging at 170 °C for 2–8 h. The heat treated samples were characterized from a microstructural and mechanical point of view and compared with both as-built and direct aging (DA) treated samples. The results show that a 15 min solution treatment at 540 °C allows the dissolution of the very fine phases obtained during the L-PBF process; the subsequent heat treatment at 170 °C for 6 h makes it possible to obtain slightly lower tensile properties compared to those of the standard T6. With respect to the DA samples, higher elongation was achieved. These results show that this heat treatment can be of great benefit for the industry.

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