Research On Controlled System Of Heat-treatment Of Drill Pipe Joint After Friction Welding Which Is Based On PLC Technology

With a great development of petroleum industry in our country, the requirement of drilling pipe is not only big quantity but also good quality. So the urgent problem which must be resolved in our petroleum industry is continual improvement of drilling pipe welding craft and qualitative control level of heat-treatment craft after welding. In order to meet the need of automation of drilling pipe heat-treatment course, the method of accomplishing heat-treatment course automation has been explore, and the basic theory which has been involved in accomplishing automation on the basis of programmable logic controller has been researched in this paper.In order to insure quality of heat treatment, we analyzed heat-treatment machine that made in our country and invented one set of apparatus, which can auto monitor the process of heat drilling pipe. It was made of PLC and industrial computer, and they were connected with communication wire. In the light of characteristic of heat-treatment machine that made in our country, we invented new type heating and cooling apparatus. We also choose the parameters of heating new drilling pipe.The experimental results indicate that the PID technology can be used in heat-treatment heating course. When appropriate parameter of P.I and D and effective anti-interaction method have been adopted, we can attain the consequence that temperature controlled precision is ±5℃ and time controlled precision is ±0.5s.According to above research and mend, the performance of domestic heating machine was improved vastly. We manufactured 250 Ton new drilling pipe with the machine. It indicated that we could weld new drilling pipe by native machine, which is important to our country economy progress.