Local Prevention of Hardening for Punching of Hot-Stamped Parts

2015 ◽  
Vol 639 ◽  
pp. 205-212 ◽  
Author(s):  
Kenichiro Mori ◽  
Tomoyoshi Maeno ◽  
Takuya Suganami
Keyword(s):  
Temperature Distribution ◽  
Laser Cutting ◽  
Heating Temperature ◽  
Resistance Heating ◽  
Hardness Distribution ◽  
Delayed Fracture ◽  
Austenitic Transformation ◽  
Sheared Edge ◽  
Heat Transfers

Punching portions of the sheet are sandwiched between the ceramic billets during rapid resistance heating to prevent hardening of these portions. When the heating temperature is locally lower than that of the austenitic transformation, i.e. below 800 oC, this portion is not hardened without occurrence of martensitic transformation, and thus cold punching of hot-stamped parts becomes easy. The ceramic billets are made of alumina and the heat transfers to the billets. The temperature distribution just after resistance heating, the hardness distribution of the hot-stamped sheet, the cold punching load, the quality of the punched hole, etc. were measured. Hardening of punching portions was successfully prevented by sandwiching between the ceramic billets. The cold punching load for the local prevention of hardening was half of that without local prevention and the delayed fracture was also prevented, whereas the drop in hardness around the sheared edge became larger than that for laser cutting.

scholarly journals Investigation of Cutting Quality of Remote DOE Laser Cutting in 0.5 mm Stainless Steel

2017 ◽  
Vol 89 ◽  
pp. 164-171
Author(s):  
Sigurd Lazic Villumsen ◽  
Morten Kristiansen
Keyword(s):  
Stainless Steel ◽  
Laser Cutting

Embedded resistive heating in composite scarf repairs

2016 ◽  
Vol 51 (18) ◽  
pp. 2575-2583 ◽  
Author(s):  
Mahdi Ashrafi ◽  
Brandon P Smith ◽  
Santosh Devasia ◽  
Mark E Tuttle
Keyword(s):  
Temperature Distribution ◽  
Outer Surface ◽  
Thermal Gradient ◽  
Thermal Damage ◽  
Electrical Current ◽  
Tensile Tests ◽  
Resistance Heating ◽  
Uniform Temperature ◽  
Uniform Temperature Distribution ◽  
Bond Strengths

Composite scarf repairs were cured using heat generated by passing an electrical current through a woven graphite-epoxy prepreg embedded in the bondline. Resistance heating using the embedded prepreg resulted in a more uniform temperature distribution in the bondline while preventing any potential thermal damage to the surface of the scarf repairs. In contrast, conventional surface heating methods such as heat blankets or heat lamps lead to large through thickness thermal gradient that causes non-uniform temperature in the bondline and overheating the outer surface adjacent to the heater. Composite scarf repair specimens were created using the proposed embedded heating approach and through the use of a heat blanket for circular and rectangular scarf configurations. Tensile tests were performed for rectangular scarf specimens, and it was shown that the bond strengths of all specimens were found to be comparable. The proposed embedded curing technique results in bond strengths that equal or exceed those achieved with external heating and avoids overheating the surface of the scarf repairs.

scholarly journals The Quality Estimation of Different Tobacco Types Examined by Headspace Vapor Analysis

1999 ◽  
Vol 18 (5) ◽  
pp. 213-222 ◽  
Author(s):  
H Hasebe ◽  
S Suhara
Keyword(s):  
Regression Model ◽  
Heating Temperature ◽  
Headspace Analysis ◽  
Principal Component ◽  
Quality Estimation ◽  
Sensory Study ◽  
Gas Chromatography Mass Spectroscopy ◽  
Vapor Analysis ◽  
Headspace Sampler

AbstractIn order to judge the quality of tobacco leaf, it is necessary to conduct sensory smoke evaluations. However, these are subjective and the results are difficult to quantify. Therefore, we have attempted to establish a quantitative method for evaluating tobacco quality by comparing results of headspace analysis. Forty-seven leaf samples of different types (flue-cured, Burley, Oriental) were analyzed. The first step in this study was to have a panel of experts smoke cigarettes made from the test tobaccos and have them evaluate 10 sensory attributes. The scores were then analyzed by the technique of principal component analysis (PCA). Results showed that the score for the flavor note attribute indicated the type of tobacco and the scores of the other 9 attributes were combined as a total to indicate smoking quality. Following the sensory study, headspace vapors of the test tobaccos were analyzed with a headspace sampler, gas chromatography, mass spectroscopy system (HS-GC-MS), in which the gas sampling loop and the HS-GC transfer line were deactivated. In order to obtain conditions for good reproducibility, the heating temperature and time of the headspace vials were examined. PCA was performed for the headspace vapor (HSV) analysis results for 31 selected peaks. The first and second principal components could be used to classify tobacco types. The third principal component partially indicated differences of smoking qualities. Finally, multiple regression analysis was performed on the HSV analysis results in order to estimate the smoking quality scores. The regression model of all samples combined had a low regression coefficient. Then, we separated the results of the three tobacco types, as we considered that the headspace data might reveal information about the classifications themselves. The final outcome was a regression model that could be applied to each type with a higher accuracy. The variables that entered the models were compared.

Optimization of the quality of laser cutting and power consumption

2007 ◽  
Author(s):  
Ch. Sipavichius ◽  
A. Amulevichius ◽  
K. Mazheika
Keyword(s):  
Power Consumption ◽  
Laser Cutting

scholarly journals Development of Black Pepper Rotary Drum Dryer System

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Ana Sakura Zainal Abidin ◽  
◽  
Mohamad Zulhatta Kifli ◽  
Annisa Jamali ◽  
Rasli Muslimen ◽  
...  
Keyword(s):  
Moisture Content ◽  
Heating Temperature ◽  
Chemical Properties ◽  
Practical Method ◽  
Black Pepper ◽  
Drying Time ◽  
Final Weight ◽  
Rotary Drum ◽  
Current Weight

Rotary drum dryer has been identified as hygienic and practical method to dry black pepper. The quality of black pepper is defined based on the chemical properties and moisture content. This research aims to develop a control system for black pepper rotary drum dryer. The dried pepper should meet the specific 12% moisture content while the heating temperature must be kept below 550C. The requirement of 12% moisture content is equivalent to 30% of the remaining weight of the pepper (final weight). The developed system uses Arduino Mega 2560 REV board as a microcontroller. A type K thermocouple with MAX6675 thermocouple amplifier and S-type load cells (TAS501) with HX711 load cell amplifier are used as input sensor to microcontroller. The system keeps measuring the current weight until it hit the targeted final weight. Two set of experiments that are using 500 g and 1500 g of pre-treated pepper were conducted to verify the system. As a result, the dryer was successful to work within the desired temperature and it stop operating just after the samples reached 12% of the moisture content. The finding has proven a shorten of drying time from 4 to 7 days when using the traditional method to the current 3 – 5 hours only when using the developed system. Hence, this is an improved method achieved to a quick drying of the black pepper.

Surface Quality of Pulsed Laser Cutting of Difficult to Machine Steel

2011 ◽  
Vol 299-300 ◽  
pp. 1016-1019
Author(s):  
Tie Jun Li ◽  
Jing Tang ◽  
Li Jun Yan ◽  
Yang Wang
Keyword(s):  
Surface Quality ◽  
Laser Cutting ◽  
Pulsed Laser ◽  
Cutting Parameters ◽  
Quality Factors ◽  
Good Separation ◽  
Machine Steel ◽  
Optimum Cutting ◽  
Super Alloy

This paper presented the experiments of Nd:YAG pulsed laser cutting of titanium alloy, super-alloy and stainless steel sheet, and investigated the influences of different laser cutting parameters on the surface quality factors focusing surface morphology. In comparison with air-, argon- and nitrogen-assisted laser cutting, argon-assisted laser cutting comes with unaffected surface quality and is suitable for laser cutting with subsequent welding requirement. With analyzing the interaction between pulses overlapping rate and energy, the results show that medium pulse overlapping rate and lower pulse rate helps to improve the surface roughness with pulsed laser cutting. And the results would be beneficial to find optimum cutting parameters for good separation surface.

Investigation of the modification effect on performance properties of cast iron molds

2021 ◽  
pp. 23-28
Author(s):  
V. A. Gulevskiy ◽  
◽  
S. N. Tsurikhin ◽  
V. V. Gulevskiy ◽  
N. Yu. Miroshkin ◽  
...  
Keyword(s):  
Cast Iron ◽  
Outer Surface ◽  
Heating Temperature ◽  
Primary Aluminum ◽  
Operating Conditions ◽  
Senior Lecturer ◽  
Advantages And Disadvantages ◽  
Stress And Deformation ◽  
Consumable Electrodes

Research is devoted to the influence of the technological method of modifying gray cast iron for the manufacture of steel casting molds. Heavy operation imposes stringent requirements both on the design of molds and on the materials from which they are made. They reliably withstand the effects of steel poured into them, having a temperature of 1600–1700 °C, thermal shock, which is directly proportional to this temperature, as well as significant effects of cyclic thermal stress and deformation. Specific operating conditions of molds (high heating temperature, their installation on movable and stationary ditches, intensive traffic flows, etc.) complicate the necessary processes directly during their operation. Modeling geometric shapes on a scale of geometric similarity 1:10. Tests were carried out on molds cast from cast iron for consumable electrodes, modified with ferrosilicon (FS65 GOST 1415-93), primary aluminum A99 (GOST 11069-2001), vanadium slag (SHVD-1 TU14-11-178-86), FSB-30) and silicomishmetal (SIMISH-1). These modifiers were chosen for modification, as they are widely used in production. Thus, the conducted studies of the nature of the deformation of the walls of the molds and the stress-strain state on models made of gray and modified cast iron make it possible to assess the advantages and disadvantages of the resulting structure and shape of graphite. Further, the methods of the rational formula of the outer surface of profiled and sheet molds are used, having predetermined the nature of destruction in advance. The use of thin-walled used rational forms can significantly reduce their specific consumption. The study of the quality of the metal cast into the experimental curved outer surface showed that the macrostructure of the metal of the experimental and ordinary ingots is the same. The work was attended by N.V Markina, senior lecturer at the Dept. of Machines and Foundry Technology, Volgograd State Technical University.

scholarly journals A characterization of quality of sheared edge in fine blanking using edge-computing approach

2018 ◽  
Vol 15 ◽  
pp. 578-583 ◽  
Author(s):  
Daniel Trauth ◽  
Joachim Stanke ◽  
Andreas Feuerhack ◽  
Thomas Bergs ◽  
Patrick Mattfeld ◽  
...  
Keyword(s):  
Edge Computing ◽  
Fine Blanking ◽  
Sheared Edge ◽  
Computing Approach

scholarly journals Research on the Molding Design and Optimization of the Molding Process Parameters of the Automobile Trunk Trim Panel

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Youmin Wang ◽  
Zhaozhe Zhu ◽  
Lingfeng Tang ◽  
Qinshuai Jiang
Keyword(s):  
Process Parameters ◽  
Heating Temperature ◽  
Process Parameter ◽  
Shrinkage Rate ◽  
Optimal Process ◽  
Molding Process ◽  
Rate Maximum ◽  
Thinning Rate ◽  
Trim Panel

In order to put forward the theoretical calculation formula for the compression force of the compression mold of the trunk trim panel, obtain the influence trend of the process parameters on the molding quality of the trunk trim panel, and obtain the optimal process parameters combination for the compression molding of the trunk trim panel, four process parameters, the heating temperature, time, compression pressure, and holding time, which affected the compression molding, were selected as the level factors; the maximum thinning rate, maximum thickening rate, and shrinkage rate of the trunk trim panel were selected as evaluation indicators and orthogonal experiments were designed and completed; the comprehensive weighted scoring method was used to obtain the comprehensive score results and obtain the comprehensive evaluation indicators of the best combination of process parameters of trunk trim panel; BP neural network and genetic algorithm were used to study the change trend of the evaluation indicators of trunk trim panel with the changes of process parameters; based on the optimal process parameter combination and the established neural network’s prediction function, the maximum thinning rate, maximum thickening rate, and shrinkage rate under a single process parameter change could be predicted, and the influence of a single process parameter on the maximum thinning rate, maximum thickening rate, and shrinkage rate could be obtained; the process parameters were optimized, and a maximum thinning rate of 28%, a maximum thickening rate of 4.3%, and a shrinkage rate of 0.8% were obtained; the optimal molding process parameters of the trunk trim panel were heating temperature of 209°C, heating time of 62 s, molding pressure of 14 kPa, and holding pressure time of 49 s; after optimization, the maximum shrinkage rate was 28.0880%, the maximum thickening rate was 44.3264%, and the shrinkage rate was 0.8901%; according to the optimal process parameters, the quality of the trunk trim panel was very good, which met the production quality requirements.

scholarly journals Effects of Casting Conditions for Reduced Pressure Test on Melt Quality of Al-Si Alloy

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1422
Author(s):  
Ho Sung Jang ◽  
Ho Jung Kang ◽  
Jin Young Park ◽  
Yoon Suk Choi ◽  
Sunmi Shin
Keyword(s):  
Sampling Method ◽  
Hydrogen Diffusion ◽  
Heating Temperature ◽  
Reduced Pressure ◽  
Hydrogen Diffusion Coefficient ◽  
Atmospheric Exposure ◽  
Pressure Test ◽  
The Difference ◽  
The One

The present study investigated the effect of the casting conditions for the reduced pressure test (RPT) on the melt quality of Al-Si alloy. The casting conditions considered in RPT were the atmospheric exposure during melting, sampling method, and mold pre-heating temperature. Density Index (DI) was measured to quantify the melt quality of the Al-Si alloy casted with the different casting conditions for the RPT. The sample with blocking atmospheric exposure during melting was 5.6% lower in DI than the one without blocking. DI showed a 1.9% gap between scooping-out and pouring sampling methods. Increasing mold pre-heating temperature from 100 °C to 250 °C increased the DI of the alloy from 8.5% to 18.7%. On the other hand, when the mold pre-heating temperature was 350 °C, the DI of the alloy dropped sharply to 0.9%. The melt quality of the alloys was analyzed by measuring the pores and microstructure and simulating the solidification of the samples. It was presumed that the oxides and inclusions in the molten alloys caused the difference in DI according to the atmospheric exposure and the sampling method. The difference in DI according to the mold pre-heating temperature could be understood by calculating the solidification starting time and hydrogen diffusion coefficient during the solidification of the alloys in RPT.

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