调质石油套管管坯的外径控制和生产工艺的探讨

DISCUSSION ON ODCONTROL AND MANUFACTURING PROCESS OFQUENCHED/TEMPERED BLANK PIPES FOR OIL CASINGS

介绍了成都无缝钢管有限责任公司原生产调质石油套管管坯的定径工艺简况。通过对Ｎ８０级石油套管管坯调质前后外径的多次测试，了解到其外径胀大的趋势，提出了相应的外径控制精度。探讨了石油套管管坯调质后热定径的工艺情况。结果表明，管坯调质后不经热定径，可生产出符合ＡＰＩ５ＣＴ要求的Ｎ８０级及以上钢级的一般高强石油套管；但是，为了获得高精度外径的石油套管，并进一步扩大品种，调质后再经热定径也是必要的。

The paper first briefly introduces the sizing process for quenched/tempered blank tubes for oil casings originally used in the facility of Chengdu Seamless Steel Tube Co.,Ltd. Based on the O.D.expansion rule learned via repeatedly measuring of O.D.of N80 casing blank tubes before and after quenching/tempering,proper tolerance of O.D. control has been set up.Also discussed are the two processes for the tubes,i.e. postquenching/tempering hotsizing process and nonpostquenching/tempering hot sizing process.The operational results show that without postquenching/tempering hotsizing treatment,it is allowable for producing ordinary histrength oil casing pipes of N80 and higher grades up to API Spec.5CT. However,to produce oil casing pipes with high O.D.accuracy and to expand the productmix,it is still a necessity to get the pipes undergo hotsizing after quenching/tempering.