Study On The Technology Of Improving The Low Power Quality Of 1Cr13 Continuous Casting Billet

The production of 1Cr13 half martensitic steel continuous casting billet center of low power quality has been as high as 3.0 on the Richter scale shrinkage problem in Dalian high alloy bar and wire rod co. Ltd. of Dong Bei special steel group company. Compression ratio is not enough in the process of rolling pipe welded poor situation. The passing rate of rod at product detection can’t achieve 80%. Because of higher level of continuous casting billet center shrinkage, this matter influenced steel product of the yield seriously.This topic, through the actual production process, using the process flow chart, causal matrix, potential failure mode analysis(FMEA), regression analysis and other tools, casting billet shrinkage cavity of 1Cr13 causes a more detailed analysis, under the condition of industrial production, applying the idea of lean six sigma, and using of the software tool by Minitab in combination with steel characteristics, solidification theory, It find out the key factor of the low shrinkage cavity. Effectively, we improve the continuous casting billet at low shrinkage cavity problem. This effectively ameliorate bases on controlling by carbon elements content, reducing the temperature dropping overall casting process control, and optimization of drawing speed, ratio of water and superheat three parameters, the actual parameters in actual production process proportion. This following result is this topic research to be obtained.(1) The C elements of 1Cr13 controlled between 0.11 and 0.14%, it can reduce the volume shrinkage from the peritectic reaction, this measure also can reduce low level of shrinkage cavity. Therefore, the C elements in steel controlling in a reasonable scope, to a certain degree of ease 1Cr13 peritectic reaction, reduce the volume shrinkage of casting process.(2) It can decrease the temperature on the stage, increased the tundish heat preservation effect, make the superheating temperature to maintain in a relatively stable state, under the condition of heating without continuously. This way reduce the degree of superheat; improve the quality of casting billet. By taking a large number of carbonized rice husk to the middle of the tundish and ladle.(3) by using the Minitab tool, we can analysis to know that is no obvious impacts from the cool water 0.23 L/kg reduced to0.19 L/kg of continuous casting billet at low shrinkagelevels in the case of other parameters unchanged. But in theory, a center of low than quantity could effectively reduce loose and shrinkage problem, due to 0.19 L/kg is the limited of the equipment than the lowest water, It has been unable to no space can be improved.(4) By using the Minitab tools analysis, we can get the optimal parameters the relationship between shrinkage cavity area and the drawing speed, degree of superheat and water. When the drawing speed of 1.00 m/min., degree of superheat is 36 ℃, water than 0.19L/kg, the continuous casting billet shrinkage was able to reach 8.98 mm2. It is the smallest.Through the production practice verification, control degree of superheat and drawing speed,the level of shrinkage cavity can be controlled below 2.0 class, the product quality are improved greatly.The parameters obtained from the experiment are used in the actual production process,proportion of continuous casting shrinkage cavity below the level can 1.5 class reaches to91.3%, and the quality improvement of continuous casting billet make the rod detection passing rate can reach to 95.8% at a time. Research methods and conclusions of the steel kind of process, it can be extended to other similar varieties of casting billet to improve their quality. It also has certain guiding significance to help us improved product quality, improved our competitiveness.