Numerical Simulation In Hevavy Ingot Solidification And The Study Of Experimental Apparatus

The quality of large forgings is closely related with the quality of steel ingots. To obtain the high-quality forged steel ingot, it must control the ingot solidification process. Ingot solidification is in the mold under high temperature inside, and difficult to direct observation and control. Although the numerical simulation of steel ingot solidification process of research, some progress is being made, but there are still many problems. Main features: results of accuracy, boundary conditions and the mathematical model of experimental support and reliability. Under laboratory conditions, to carry out large-scale ingot solidification process on the physical simulation study, not only to understand the main factors affecting the solidification process and defect formation mechanism, but also for the corresponding numerical simulation experiment to provide the necessary support to control the quality of steel ingots of great significance, is also an important guarantee of high quality forgings.In this paper, a large steel ingot solidification process is studied through a large steel ingot solidification process on the three-dimensional numerical simulation of temperature field, a large steel ingot center longitudinal study on the variation of cooling rate; to simulate the cooling of large ingot center longitudinal velocity the initial target for the solidification simulation device design and fabrication. The major findings are as follows:1) The large-scale ingot solidification process on the temperature field simulation results show that: the solidification of steel ingot by the axial trend of steel ingot ingot bottom riser to the Department forward, radial steel ingot from the mold wall to the center gradually. Vertical section in the center of ingot, the ingot solidification process of the cooling rate in the 10-3 ~ 10-1℃/ s between the change in magnitude.2) The Niyama criterion function of the ingot shrinkage, porosity was predicted, results showed that: ingot shrinkage concentrated in the riser area, center of osteoporosis occur within the ingot.3) To simulate the longitudinal center of a large steel ingot solidification cooling rate target, design and produce a set of solidification simulation experimental installation.4) In the development of solidification simulation device, respectively, using the T10 steel and Pb-Sn alloy ingot to simulate the solidification process of the experimental results of calculations show that: in the present conditions, the device can be realized in the cooling rate of molten steel 10 -1℃/ S under the orders of magnitude the solidification simulation; tin-lead alloy in the cooling rate of 10-2℃/ S orders of magnitude under the solidification simulation.5) The use of solidification simulation device developed to study the solidification conditions on the segregation. After the solidification of tin-lead alloy ingots of composition analysis showed that: alloy ingot segregation of low melting point solute enrichment channel Sn; different locations on the longitudinal profile component test results showed that: there is segregation of alloy ingots at the top, the bottom of the negative segregation, the largest segregation ratio is 1.57.