scholarly journals The influence of soak temperature and forging lubricant on surface properties of steel forgings

2020 ◽  
Author(s):  
S. Hill ◽  
R. P. Turner ◽  
P. Wardle
Keyword(s):  
Surface Roughness ◽  
Surface Hardness ◽  
Lower Surface ◽  
Design Parameters ◽  
Compression Tests ◽  
Molybdenum Disulphide ◽  
Small Series ◽  
Ring Compression ◽  
Water Based ◽  
The Impact

AbstractA small series of ring compression tests were performed on BS970:708M40 alloy steel. The samples were tested using a 2-factor temperature variable, and a 4-factor lubricant variable, as the design parameters. Two differing soak temperatures were used, namely 1030 °C and 1300 °C respectively. The lubricants applied at the billet to tooling interface were synthetic water–based, graphite water–based, graphite and molybdenum disulphide viscous grease, and finally, unlubricated samples were tested. The ring compression tests were performed using a traditional drop forging hammer and induction heating to minimise any unintentional process variability. The impact that the two varying process parameters have upon the compression sample was then assessed by measuring each sample’s surface hardness and surface roughness prior to and post forging with fully calibrated equipment. It was demonstrated that the higher soak temperature of 1300 °C yielded a lower surface hardness value and higher surface roughness than the lower soak temperature, 1030 °C. The two water-based lubricants offered negligible change in results compared with the unlubricated forging, strongly suggesting that the lubricants were evaporated off the surface prior to forging. However, the results from the graphite–molybdenum disulphate grease do indicate in particular higher surface roughness than other lubricants, and a non-symmetric distortion pattern.

scholarly journals Thermo-mechanical forging of 708M40 steel ring samples: experiments and modelling

2021 ◽  
Author(s):  
Steven Hill ◽  
Richard P.Turner
Keyword(s):  
Finite Element ◽  
Experimental Parameter ◽  
Compression Tests ◽  
Molybdenum Disulphide ◽  
Heating Unit ◽  
Modelling Framework ◽  
Process Understanding ◽  
Ring Compression ◽  
Water Based ◽  
Temperature Variable

AbstractA series of ring compression tests using BS970:708M40 alloy steel samples were studied. These tests were conducted using a 2-factor soak-temperature variable, namely 1030 °C and 1300 °C, and a 4-factor lubricant variable consisting of unlubricated samples, synthetic water-based, graphite water-based, and graphite and molybdenum disulphide viscous grease. The lubricant agents were all applied to the tool/billet interface. Process variables such as blow force and heating were controlled with the use of a gravitationally operated drop hammer and an automated programmable induction-heating unit. This matrix of the experimental parameters offered a sound base for exploring dominant factors impacting upon bulk deformation. This deformation was measured using fully calibrated equipment and then systematically recorded. A finite element modelling framework was developed to further improve the thermo-mechanical deformation process understanding, with finite element (FE) predictions validated through experimental measurement. Through the combined experimental and FE work, it was shown that temperature variation in the experimental parameter matrix played a larger role in determining deformation than the lubrication agent. Additionally, the use of synthetic and graphite water-based lubricants does not necessarily produce greater deformation when used in high-temperature forgings due to the lubricants breaking down, evaporating, or inducing rapid billet cooling as a result of the carrier used (water). Graphite-molybdenum disulphate grease far outperforms the other lubricants used in this trial in reducing friction and allowing deformation to occur across a die-face.

scholarly journals Eco-Friendly Water-Based Nanolubricants for Industrial-Scale Hot Steel Rolling

Lubricants ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 96
Author(s):  
Hui Wu ◽  
Hamidreza Kamali ◽  
Mingshuai Huo ◽  
Fei Lin ◽  
Shuiquan Huang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Oxide Scale ◽  
Rolling Force ◽  
Pure Water ◽  
Surface Hardness ◽  
Industrial Scale ◽  
Steel Rolling ◽  
Scale Thickness ◽  
Lubrication Performance ◽  
Water Based

Eco-friendly and low-cost water-based nanolubricants containing rutile TiO2 nanoparticles (NPs) were developed for accelerating their applications in industrial-scale hot steel rolling. The lubrication performance of developed nanolubricants was evaluated in a 2-high Hille 100 experimental rolling mill at a rolling temperature of 850 °C in comparison to that of pure water. The results indicate that the use of nanolubricant enables one to decrease the rolling force, reduce the surface roughness and the oxide scale thickness, and enhance the surface hardness. In particular, the nanolubricant consisting of 4 wt % TiO2, 10 wt % glycerol, 0.2 wt % sodium dodecyl benzene sulfonate (SDBS) and 1 wt % Snailcool exhibits the best lubrication performance by lowering the rolling force, surface roughness and oxide scale thickness by up to 8.1%, 53.7% and 50%, respectively. The surface hardness is increased by 4.4%. The corresponding lubrication mechanisms are attributed to its superior wettability and thermal conductivity associated with the synergistic effect of rolling, mending and laminae forming that are contributed by TiO2 NPs.

scholarly journals Eco-friendly Water-based Nanolubricants for Industrial-scale Hot Steel Rolling

2020 ◽  
Author(s):  
Hui Wu ◽  
Hamidreza Kamali ◽  
Mingshuai Huo ◽  
Fei Lin ◽  
Shuiquan Huang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Oxide Scale ◽  
Rolling Force ◽  
Pure Water ◽  
Surface Hardness ◽  
Industrial Scale ◽  
Steel Rolling ◽  
Scale Thickness ◽  
Lubrication Performance ◽  
Water Based

Eco-friendly and low-cost water-based nanolubricants containing rutile TiO2 nanoparticles (NPs) were developed for accelerating their applications in industrial-scale hot steel rolling. The lubrication performance of developed nanolubricants was evaluated in a 2-high Hille 100 experimental rolling mill at a rolling temperature of 850 ℃ in comparison to that of pure water. The results indicate that the use of nanolubricant enables to decrease the rolling force, reduce the surface roughness and the oxide scale thickness, and enhance the surface hardness. In particular, the nanolubricant consisting of 4 wt% TiO2, 10 wt% glycerol, 0.2 wt% sodium dodecyl benzene sulfonate (SDBS) and 1 wt% Snailcool exhibits the best lubrication performance by lowering the rolling force, surface roughness and oxide scale thickness up to 8.1%, 53.7% and 50%, respectively. The surface hardness is increased by 4.4%. The corresponding lubrication mechanisms are attributed to its superior wettability and thermal conductivity associated with the synergistic effect of rolling, mending and laminae forming that are contributed by TiO2 NPs.

Influence of Laser Shot Peening Parameters on the Surface Hardness and Roughness of 7075 Aluminum Alloy

2018 ◽  
Vol 920 ◽  
pp. 83-88
Author(s):  
Jun Hao Zhang ◽  
Xiu Quan Cheng ◽  
Qin Xiang Xia ◽  
Jia Yu Li
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Shot Peening ◽  
Surface Hardness ◽  
Laser Shot ◽  
7075 Aluminum Alloy ◽  
Alloy Specimen ◽  
Structural Parts ◽  
The Impact ◽  
Overlap Rate

The laser shot peening has the widely application prospect in aircraft structural parts repairment. The influence of laser shot peening parameters on the surface hardness and surface roughness has guiding significance for laser shot peening process. The variation law of surface hardness and surface roughness in the peening area of 7075 aluminum alloy were obtained based on the experiment research. The results show that the surface hardness improves effectively after laser shot peening, and the maximum hardness is 205.4HV, which is improved by 19.49% compared with the original hardness. Besides, the surface roughness of the rough specimen decreases; whereas, those of the smooth specimen increases after laser shot peening. However, both the surface hardness and surface roughness tend to be saturated when the impact times exceeds 3 times or the overlap rate exceeds 50%. Therefore, a good repairment effect can be obtained with 3 impact times and 50% overlap rate for the 7075 aluminum alloy specimen.

scholarly journals Investigation and Statistical Modeling of the Mechanical Properties of Additively Manufactured Lattices

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3962
Author(s):  
Derek G. Spear ◽  
Anthony N. Palazotto
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Design Parameters ◽  
Statistical Experimental Design ◽  
Lattice Structures ◽  
Compression Tests ◽  
Static Compression ◽  
Interaction Terms ◽  
Cell Densities ◽  
The Impact

This paper describes the background, test methodology, and experimental results associated with the testing and analysis of quasi-static compression testing of additively manufactured open-cell lattice structures. The study aims to examine the effect of lattice topology, cell size, cell density, and surface thickness on the mechanical properties of lattice structures. Three lattice designs were chosen, the Diamond, I-WP, and Primitive Triply Periodic Minimal Surfaces (TPMSs). Uniaxial compression tests were conducted for every combination of the three lattice designs, three cell sizes, three cell densities, and three surface thicknesses. In order to perform an efficient experiment and gain the most information possible, a four-factor statistical experimental design was planned and followed throughout testing. A full four-factor statistical model was produced, along with a reduced interactions model, separating the model by the significance of each factor and interaction terms. The impact of each factor was analyzed and interpreted from the resulting data, and then conclusions were made about the effects of the design parameters on the resultant mechanical performance.

Multiscale Parallelized Computational Fluid Dynamics Modeling Toward Resolving Manufacturable Roughness

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Marios Kapsis ◽  
Li He ◽  
Yan Sheng Li ◽  
Omar Valero ◽  
Roger Wells ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Surface Roughness ◽  
Large Scale ◽  
Design Parameters ◽  
Flow Structures ◽  
Multiscale Approach ◽  
Local Flow ◽  
The Impact ◽  
Micro Elements

Abstract Typical turbomachinery aerothermal problems of practical interest are characterized by flow structures of wide-ranging scales, which interact with each other. Such multiscale interactions can be observed between the flow structures produced by surface roughness and by the bulk flow patterns. Moreover, additive manufacturing (AM) may sooner or later open a new chapter in the way components are designed by granting designers the ability to control the shape and patterns of surface roughness. As a result, surface finish, which so far has been treated largely as a stochastic trait, can be shifted to a set of design parameters that consist of repetitive, discrete micro-elements on a wall surface (“manufacturable roughness”). Considering this prospective capability, the question would arise regarding how surface microstructures can be incorporated in computational analyses during designing in the future. Semi-empirical methods for predicting aerothermal characteristics and the impact of manufacturable roughness could be used to minimize computational cost. However, the lack of element-to-element resolution may lead to erroneous predictions, as the interactions among the roughness micro-elements have been shown to be significant for adequate performance predictions (Kapsis and He, 2018, “Analysis of Aerothermal Characteristics of Surface Micro-Structures,” ASME J. Fluids Eng., 140(5), p. 051104). In this paper, a new multiscale approach based on the novel block spectral method (BSM) is adopted. This method aims to provide efficient resolution of the detailed local flow variation in space and time of the large-scale microstructures. This resolution is provided without resorting to modeling every single ones in detail, as a conventional large-scale computational fluid dynamics (CFD) simulation would demand, but still demonstrating similar time-accurate and time-averaged flow properties. The main emphasis of this work is to develop a parallelized solver of the method to enable tackling large problems. The work also includes a first of the kind verification and demonstration of the method for wall surfaces with a large number of microstructured elements.

Surface roughness and material strength of tribo-pairs in ring compression tests

2011 ◽  
Vol 44 (2) ◽  
pp. 134-143 ◽  
Author(s):  
V.A.M. Cristino ◽  
P.A.R. Rosa ◽  
P.A.F. Martins
Keyword(s):  
Surface Roughness ◽  
Material Strength ◽  
Compression Tests ◽  
Ring Compression

Analysis of Friction in Ring Compression: A Factorial Experiment

1972 ◽  
Vol 94 (4) ◽  
pp. 1189-1192 ◽  
Author(s):  
A. Mulc ◽  
S. Kalpakjian
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Coefficient Of Friction ◽  
Factorial Experiment ◽  
Compression Tests ◽  
Ring Compression ◽  
The Coefficient Of Friction ◽  
Deformation Surface ◽  
Factorial Plan

The influence of lubricant, rate of deformation, surface roughness, deformation, and temperature on the coefficient of friction of three types of aluminum were studied using ring-compression tests. The experiments were designed according to the factorial plan 24; namely, four variables were investigated at two levels each. The order of importance of these variables were established for each aluminum alloy and at room and elevated temperature.

scholarly journals Wear Performance of Boronized Layer of Iron-based Powder Metallurgy Materials

2021 ◽  
Author(s):  
Huimin FANG ◽  
Liansen XIA ◽  
Qingping YU ◽  
Guangsheng ZHANG
Keyword(s):  
Surface Roughness ◽  
Powder Metallurgy ◽  
Friction Coefficient ◽  
Friction And Wear ◽  
Wear Track ◽  
Surface Hardness ◽  
Lower Surface ◽  
Dual Phase ◽  
Wear Performance ◽  
Iron Based

Iron-based specimens with boronized layers were prepared by boriding at 800 ℃, 900 ℃ and 1000 ℃ for 3, 5, and 7 hours, respectively. The thickness, microstructure, surface roughness, friction, and wear performance were studied. Results showed that the process parameters such as temperature, the time of boriding have remarkable impact on the thickness of the boronized layer. Dual-phase was generated at 1000 ℃ which lead to increased brittleness, lower surface hardness, and decreased adhesion to the substrate. Compared with specimens boronized at 1000 ℃ and 800 ℃, the surface structure of the boronized layer of specimens boronized at 900 ℃ is denser and uniform, the wear track is not damaged. The average friction coefficient and mass loss by wear of specimens boronized at 900 °C are smaller than that of boronized at 1000 ℃ and 800 ℃, indicating that specimens borided at 900 ℃ behave excellent friction and wear performance.

Investigation about Electro-Deposition Properties of Special Nickel Electroplating Coating for 45# Steel with Different Surface Roughnesses

2010 ◽  
Vol 146-147 ◽  
pp. 962-965 ◽  
Author(s):  
Wei Lin Zhao ◽  
Hui Huang ◽  
Zhen Lin Wang
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Adhesion Force ◽  
Surface Hardness ◽  
Lower Surface ◽  
Electro Deposition ◽  
Resistance Surface ◽  
Nickel Electroplating

The effects of the surface roughness on electro-deposition properties of the special nickel electroplating coating for the 45# steel were investigated. The results indicate that the surface roughness has great effects on the corrosion resistance and the surface hardness of the coating, the adhesion force between the coating and the substrate. Among the three 45# samples with different surface roughnesses, the sample with moderate surface roughness (Ra≈0.1um) has the relatively higher corrosion resistance, surface hardness and adhesion force than the samples with higher and lower surface roughness.

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