Cooling process optimization during hardening steel in water polyalkylene glycol solutions

Objects of investigations are water solutions of polyalkylene glycol (PAG) which are used as the quenchants in the heat-treating industry. They are tested by standard cylindrical probe made of Inconel 600 material. The main and not solved yet is the problem of transition from data achieved for standard probe to data suitable for any form and size of real steel part. It opens possibility to make predictable calculations. Taken this into account, it has been investigated water solutions of PAG of different concentration. It is underlined that cooling intensity of quenchant can be evaluated by Kondratiev number Kn. The mentioned number Kn varies within 0≤Kn≤1 when generalized Biot Biv number varies within 0≤Biv≤∞. As a main achievement of investigation is established correlation between standard Kn number and Kn number of real steel part. In many cases, when film boiling is absent, the established correlation is a linear function. It allows optimizing quenching processes: obtain high surface compressive residual stresses, save alloy elements and improve environment condition. All of this is achieved by tolerating chemical composition of steel with size and form of quenched object as it is proposed by UA Patent No. 114174. Also, the number Kn allows interruption of quench process when surface compressive residual stresses are at their maximum value that essentially improves the quality of steel components. Moreover, interrupted cooling prevents quench crack formation, decreases distortion of quenched steel parts. The results of investigations can be used by engineers in the heat-treating industry and scientists for further research.

Automated process control system of Jaw crusher production

Rocks go through a series of crushing stages to produce the final aggregate size which suit customer’s needs. Aggregate crushers suffer from many problems in reality that affect its production processes badly and may lead to its stoppage. These problems could be unchangeable feed rate, hidden steel part between rocks and wastage from storing final aggregate stockpile on the ground. The purpose of this research is to develop an automated control system for Jaw crusher production process as a solution for the real specified problems to get more productive aggregate production. First a 3D model which mimic exactly the real crushing plant was built to test the proposed system. Then a C++ code was programmed to control the proposed system components such as motor, sensors and LCD screens. Thereafter, the aggregate flow simulation program (AggFlow) is utilized to simulate the proposed system results. Cost analysis calculations were performed to explore the impact of proposed system on the production process cost and time. Finally, the results confirmed that the proposed system enhance and increase the crusher production process. As it shows increase in the crusher automatic control, the net profit and the feed rate while decrease in the final product waste.

The Comparison of Microstructure and Mechanical Behavior of Stainless Steel 316L Using Near Net Shaped and Fully Embedded Methodologies Using DED Metal Advanced Manufacturing

The objective of this research is to compare the microstructure and mechanical behavior of 3D printed SS 316L using near net shaped and fully embedded manufacturing extraction techniques. Research findings will allow us to determine if two different manufacturing extraction methodologies of a 3D printed stainless steel part will affect the overall performance of test specimens. Research will implement advanced manufacturing, part designing, part modeling, part simulation, part production, CT X-ray scanning, material characterization, and material testing. Printing of test specimens will be done with a Optomec Lens 3D Hybrid Machine Tool Direct Energy Deposition (DED) metal printer. The DED metal printer will be used for prototype printing and printing test samples. The areas of study will also include modeling and design using SolidWorks CAD software. A comparison of printing orientation/configuration, internal composition, and testing of material structure in the areas of stress to complete failure of test specimens. The internal structure analysis will observe the porosity effects of 3D metal printing with near net shaped and cocoon style print parameters. The study will also address the amount of time, production, strength, composition, and overall performance of SS 316L printed material.

Finite Element Modelling for Structural Performance of Slim Floors in Fire and Influence of Protection Materials

Slim floor systems are very common nowadays and various types are currently being used for the construction of high-rise buildings and car parks. Concrete in slim floor beams encases the steel beam section which helps to improve their fire resistance. Despite their higher fire resistance, several fire protection materials like intumescent coatings are often used to achieve a higher fire resistance where desired. The thermal properties and behaviour of various intumescent coating materials were previously studied through experimental investigations. This paper presents finite element analyses to simulate the response of unprotected and protected slim floor beams in fire using different simulation tools. For this purpose, fire tests conducted on unprotected slim floor beams and intumescent coating materials are modelled using research and commercial software. Results from the analyses are compared and verified with the available test data. These validated models are later combined to study the behaviour of protected slim floor beams in fire. Results from the study show that the research and the commercial software replicate the behaviour of slim floor beams and protection materials with good accuracy. Due to the presence of the intumescent coating, the protected slim floor beams displayed a better fire resistance as the temperature of the steel part remained below 400 °C even after 60-min of standard heating. The protected slim floor beams continued to support the external loads even after 120 min of heating.