Research On The Structural Design And Grinding Performance Of Underwater Vertical Diamond Wire Saw

Marine oil and gas resources have far-reaching strategic significance and significant practical significance,which are an important part of the national energy supply.Offshore oil and gas platforms are essential facilities for offshore oil and gas exploration,and marine oil and gas pipelines are essential means for marine oil and gas transportation.With the rapid development of marine oil and gas resources exploitation,abandoned offshore oil and gas platforms and long-serving marine oil and gas pipelines have increased year by year.Demolition of abandoned offshore oil and gas platforms and maintenance of failed oil and gas pipelines are urgent.Getting rid of foreign technical restrictions,achieving security economy pipeline demolition and stabilize efficient pipeline maintenance by relying on domestic technology and equipment are the urgent need for the development of China's offshore oil industry.The research work of this subject is carried out by the National Natural Science Foundation of China,"Research on Cutting and Wear Characteristics of Diamond Beaded Rope Cutting Steel-Based Materials in Deep Water Environment"(Project No.: 5160751260).The purpose of the project is to develop an underwater diamond wire saw that can cut marine risers of 20 " to 30"(?508 ~ 762mm)steel-based composite materials.The working environment of the underwater diamond wire sawing machine was clarified,the operation flow of the underwater diamond wire sawing machine was planned,the overall design scheme of the underwater riser diamond wire saw was determined,and the key technologies were studied.The process of cutting the marine riser by the diamond wire saw is the grinding process of a large number of diamond beads to the steel-based material.The diamond bead grinding process is a combination of a large number of diamond abrasive grains discretely distributed on the surface of the diamond bead to complete the sliding,ploughing and grinding action.The kinetic simulation model of grinding the X65 pipeline steel with a single diamond abrasive grain was established.The effects of grinding speed,grinding depth and abrasive rake angle on the grinding process of diamond abrasive grains were analyzed,which were used to determine the appropriate process parameters when the stringed bead cuts the marine riser in different situations.The generation of grinding force during the grinding of diamond abrasive grains is theoretically predicted.Combined with the dynamic simulation model of diamond abrasive grain grinding X65 pipeline steel,the influence characteristics of the process parameters on the grinding force are deeply analyzed.Aiming at the requirement of the diamond bead matrix to the holding force of the diamond abrasive grains in practical application,the feasibility proposal of the diamond bead manufacturing process is proposed to improve the performance of diamond bead cutting workpieces.Based on the simulation analysis of single diamond abrasive grinding,the dynamic simulation model of diamond bead grinding pipeline steel was established.The effect of abrasive density on diamond bead on the pipeline steel surface processing properties and grinding force was studied.The modified friction and wear tester was used to carry out the relevant tests of diamond bead grinding,and the test results were compared with the simulation results.Analysis result lays a foundation for the follow-up research of diamond bead grinding steel-based materials.