The ultra-high temperature forging process based on DEFORM-3D simulation

Author(s):  
Yong-qiang Wu ◽  
Kai-kun Wang
2021 ◽  
Author(s):  
Wu Yong-qiang ◽  
Wang Kai-kun

Abstract Green manufacturing and forming technology is becoming increasingly important in modern industry. In this study, a new forging technology with the ultra-high temperature demoulding is introduced, in which conventional reheating process could be avoided. The DEFORM-3D software simulated the forging process and the temperature fields were obtained. The traditional forging process was simulated when the initial forging temperature was 1220℃. The highest temperature of the ingot in the new forging technology was about 200℃ higher than that of the traditional forging process. We cut the ingot longitudinally along the centerline. Nine points on the axis of the cutting plane and nine points on the radial direction were selected. The equivalent stress and the equivalent strain of these points were compared respectively under the two forging processes by using the particle tracking method. The variation laws of the equivalent stress and the equivalent strain with the reduction were obtained. According to the variation laws, the typical points which were easy to crack under two different forging processes were found. Based on the flow stress-strain curve calculated by the software JMatPro®, the new forging technology could avoid hot cracking.


2021 ◽  
Author(s):  
yongqiang wu ◽  
Zhi-ren Sun ◽  
Kaikun Wang

Abstract During the preparation of the ingot with liquid core in the early stage, the finite element models of the solidification and the ultra-high temperature demoulding were established in DEFORM-3D. The thermophysical properties of ASSAB 718 with the variations of C, Mn and Cr were calculated in JMatPro®. The material database was imported into DEFORM-3D. Through the analysis of the finite element simulation results, we obtained the influence of three main elements C, Mn and Cr contents on the size of the solid-phase region, the liquid-phase region and the solid-liquid two-phase region in the ingot. We optimized the composition of the material to get a wide solid-liquid phase range. The high carbon, the medium manganese and the high chromium contents were beneficial to form the liquid core. Based on the method of the solidification time, the algorithm was programmed by the python language. We analyzed the influence of the three elements C, Mn, and Cr on the concentration distribution based on the temperature field data, which were obtained by DEFORM-2D after the solidification and the ultra-high temperature demoulding. According to the simulation results, we found that the region prone to negative segregation.


2020 ◽  
Vol 16 (8) ◽  
pp. 1183-1195
Author(s):  
Prasad Rasane ◽  
Nitya Sharma ◽  
Sana Fatma ◽  
Sawinder Kaur ◽  
Alok Jha ◽  
...  

Background: Background: Milk forms an integral part of the human diet from the nutritional point of view. Besides nutrition, it has also unique functional properties which are harnessed by the industry for numerous uses. Being highly perishable specific techniques are required to minimize the losses during processing and adequate preservation of this precious commodity. In the U.S. and many other parts of the world, the traditional pasteurization of milk requires a minimum heat treatment of 72ºC for 15 seconds with subsequent refrigeration. However, the advent of Ultra High Temperature (UHT) treatment of milk has added a new dimension to the marketing of liquid milk in urban as well as remote areas without the requirement of cold chain management. The distinctive feature of UHT processed milk is that it is commercially-sterile-not pasteurized and so has long shelf life at room temperature. UHT milk, also known as long-life milk, is emerging as an attractive commercial alternative offering a hygienic product of unmatched quality, which can be bought anywhere, at any time and in any quantity. The present review will discuss numerous aspects of UHT processing of milk with reference to historical significance, fundamental principle, various systems used and prerequisites, type of exchangers used, fouling and other defects in system, chemical and microbiological effect of the treatment, its effect on nutritional components, organoleptic quality of milk and the advantage and involved challenges of the process. Conclusion: Raw milk is easily contaminated with pathogens and microbes and hence its consumption of raw milk is associated with certain ill health effects. Therefore, heating milk before consumption is strongly suggested. Thus, UHT treatment of milk is done to ensure microbial safety and also to extend the shelf life of this highly perishable commodity. Heating milk at such a high temperature is often associated with the change of organoleptic properties like change in flavor or cooked flavor, rancidity due to microbes or acid flavor, etc. But UHT treatment does not substantially decrease the nutritional value or any other benefits of milk.


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