Research On Anatomical Experiment For Water And Riser Of Large Ingot

The heavy forging manufacturing is a key industry in our defense construction and development of national economy,Which is also the basis of major equipment manufacturing industry and the important component of national capacity.And the level of product,production capacity and developmental level of the heavy forging manufacturing has became to a sign of national comprehensive industrial level.The integrated and large-scaled development of industrial production equipment has put forward a higher demands on the heavy forgings and ingots.Based on the chemical composition,macroscopic structure,inclusions and microstructure analysis for nozzle and riser samples of 231t,300t and 438t large ingots through anatomical experiments and computer numerical simulation.This paper studied the distribution and formation regularity of ingot defects and modified the simulation software "FTINGOT".Then the smelting and casting process were optimized,the conditions of ingot solidification were improved and the segregation of ingot was reduced.C and Mo element have a small amount of negative segregation at the edge of the riser and a massive positive segregation in the center.And have an upward trend from the edge to the center at different heights.The positive segregation will be higher with closing to the center of the riser.There is a negative segregation at the upside of the center and a small amount of positive segregation at the edge and the bottom in the water.And the degree of segregation is smaller than that of riser.There is banded segregation in the longitudinal section of the riser,which tends to be more serious with the increase of ingot type,But this phenomenon is relatively minor in the nozzle.In all,The quality of the nozzle is generally good,And there is severe segregation and mang inclusions of larger particles in the water.The modified simulation software "FTINGOT" could simulate the formation process of segregation defect in the ingot solidification process very well and forecast the degree of segregation and the final position.The numerical simulation and anatomic results shows that:The anatomical analysis results of negative segregation zone in the water grees well with the simulation results.There is obvious difference in the positive segregation zone in the riser center,While the overall trend is consistent.Based on the calculation results,we can master the formation rule of defects and take corresponding measures to control it,Then as much as possible to reduce the number of defects.