海洋平台桩腿齿条氧气切割热影响区组织与性能

Microstructure and properties of heat affected zone in gear rack used in offshore platform processed by oxyfuel gas cutting

自升式钻井平台由于其定位能力强和作业稳定性好，在大陆架海域的油气勘探开发中居主力军地位。桩腿齿条是自升式钻井平台升降系统的核心部件。是整个平台建造的关键。基于海洋钻井平台桩腿齿条精密氧气切割试验，试验分析桩腿齿条氧气切割断面热影响区宽度、分布趋势、金相组织及硬度。在桩腿齿条切割断面热影响区宽度约2．7～19．5mm，其中齿条上层、下层及齿顶处区域宽度较宽。同时由于金相组织变化及切割过程增碳作用，导致热影响区硬度较大幅度升高．而齿条内部则保留了原母材组织特点及高强度等性能，这一特点符合桩腿齿条承载大载荷且具有较好的耐磨性的要求，有利于提高海洋平台桩腿齿条的耐磨性及使用寿命。试验及分析结果表明，中国目前对于250mm厚的钢板的精密氧气切割技术是成熟可靠的，完全能够满足桩腿齿条的自主生产需要。

Jack-up drilling platform is on dominant position in oil and gas exploration of the continental shelf area,which is capable to fix position accurately and work stably.The gear rack is one of the key components of the jacking system which is the crux of the platform.Macroscopic morphology and microstructure were analyzed to study the effects of gas cutting process on the gear rack.The results demonstrated that the precision cutting technology used in steel plate with the thickness of 250 mm are reliable to meet the needs of the manufacturing of gear racks,which are run up to the advanced levels in the world.