D0I:10.13374/i.issnl001153.2009.02.020 第31卷第2期 北京科技大学学报 Vol.31 No.2 2009年2月 Journal of University of Science and Technology Beijing Feh.2009 变形量及N含量对油井管用中碳V一TiN微合金钢 显微组织的影响 许磊)刘国权山2) 吴凯) 1)北京科技大学材料科学与工程学院，北京100083 2)北京科技大学新金属材料国家重点实验室，北京100083 摘要采用Gleeble-一l5O0热模拟试验机，研究了某油井管生产工艺中张力减径过程变形量以及C和N含量对中碳V一Ti一 N微合金非调质钢室温组织的影响.结果表明：HCLN钢在800℃变形量为20%、40%和60%时，对应的室温组织中铁素体的 体积分数依次为17.2%、19.7%和29.9%.N质量分数为2.3×10-4时，800℃变形60%后控冷钢中铁素体的体积分数为含 低N(1.1×10-4)钢的1.7倍左右，使含C0.34%的钢中铁素体含量接近于含C0.26%的钢，并使铁素体平均晶粒尺寸降低 到3“左右·变形量和钢中N含量二者增大均有利于增加钢中铁素体的数量，且二者综合运用的效果更有效，通过分析可 知，800℃变形量的增大，可以提高未再结晶奥氏体晶粒内的缺陷密度，有利于过冷奥氏体连续冷却转变时为晶内铁素体形核 提供更多的形核位置.N含量的增大，能够促进第二相析出物的析出，诱导晶内铁素体的析出，提高铁素体含量，并细化其晶 粒尺寸 关键词微合金钢：热变形：碳：氨：晶内铁素体 分类号TG142.33:TG111.7 Influence of deformation and N content on the microstructure of medium-carbon V-Ti-N microalloyed steels for oil-well tubes XU Lei.2),LIU Guo-quan.2),WU Kai) 1)School of Materials Science and Engineering.University of Science and Technology Beijing.Beijing 100083.China 2)State Key Laboratory for Advanced Metals and Materials.University of Science and Technology Beijing.Beijing 100083.China ABSTRACT The influence of deformation during stretch reducing.C and N contents on the microstructure of medium-carbon V-Ti- N microalloyed steels for oil-well tubes was investigated with a Gleeble-1500 simulator.The results show that the volume fractions of ferrite in HCLN steel with deformations of 20%.40%and 60%at 800 C are 17.2%.19.7%and 29.9%.respectively.The amount of ferrite in HCHN steel with an N content of 2.3X10is almost equal to that in LCLN steel with a C content of 0.26%, and 1.7 times that in HCLN steel with an N content of 1.1X10.However.the size of ferrite grains in HCHN steel is about 3m, the smallest among the experimental steels.It is obvious that increasing deformation and N content is beneficial to the amount of fer- rite,and it is more effective that deformation and N are used simultaneously.According to analyses,when the degree of deformation enlarges,defects in non-recrystallized austenite grains increase,which is helpful to provide plenty of nucleation sites for intragranular ferrite.While increasing the content of N to 2.3X10,second phase precipitation is promoted.the amount of ferrite increases,and ferrite grains are refined simultaneously. KEY WORDS microalloyed steel:hot deformation:carbon:nitrogen:intragranular ferrite 中碳微合金非调质钢是在中碳钢基础上添加微 变形和热处理工艺相结合的一种低合金高强度钢. 量合金元素V、Ti和Nb等强碳化物形成元素，并将 与调质钢相比，节减了热处理工序，避免在热处理过 收稿日期：2008-02-27 基金项目：国家自然科学基金资助项目(N。·5027I009):国际钒技术委员会(VANITEC)资助项目 作者简介：许磊(1980-)，男，博士研究生；刘国权(1952-)，男，教授，博士生导师，g-lim@ustb.edu.cn变形量及 N 含量对油井管用中碳 V－Ti－N 微合金钢 显微组织的影响 许 磊1‚2） 刘国权1‚2） 吴 凯1） 1） 北京科技大学材料科学与工程学院‚北京100083 2） 北京科技大学新金属材料国家重点实验室‚北京100083 摘 要 采用 Gleeble－1500热模拟试验机‚研究了某油井管生产工艺中张力减径过程变形量以及 C 和 N 含量对中碳 V－Ti－ N 微合金非调质钢室温组织的影响．结果表明：HCLN 钢在800℃变形量为20％、40％和60％时‚对应的室温组织中铁素体的 体积分数依次为17∙2％、19∙7％和29∙9％．N 质量分数为2∙3×10－4时‚800℃变形60％后控冷钢中铁素体的体积分数为含 低 N （1∙1×10－4）钢的1∙7倍左右‚使含 C0∙34％的钢中铁素体含量接近于含 C0∙26％的钢‚并使铁素体平均晶粒尺寸降低 到3μm 左右．变形量和钢中 N 含量二者增大均有利于增加钢中铁素体的数量‚且二者综合运用的效果更有效．通过分析可 知‚800℃变形量的增大‚可以提高未再结晶奥氏体晶粒内的缺陷密度‚有利于过冷奥氏体连续冷却转变时为晶内铁素体形核 提供更多的形核位置．N 含量的增大‚能够促进第二相析出物的析出‚诱导晶内铁素体的析出‚提高铁素体含量‚并细化其晶 粒尺寸． 关键词 微合金钢；热变形；碳；氮；晶内铁素体 分类号 TG142∙33；TG111∙7 Influence of deformation and N content on the microstructure of medium-carbon V-T-i N microalloyed steels for oi-l well tubes XU Lei 1‚2）‚LIU Guo-quan 1‚2）‚W U Kai 1） 1） School of Materials Science and Engineering‚University of Science and Technology Beijing‚Beijing100083‚China 2） State Key Laboratory for Advanced Metals and Materials‚University of Science and Technology Beijing‚Beijing100083‚China ABSTRACT T he influence of deformation during stretch reducing‚C and N contents on the microstructure of medium-carbon V-T-i N microalloyed steels for oi-l well tubes was investigated with a Gleeble-1500simulator．T he results show that the volume fractions of ferrite in HCLN steel with deformations of 20％‚40％ and 60％ at 800℃ are 17∙2％‚19∙7％ and 29∙9％‚respectively．T he amount of ferrite in HCHN steel with an N content of 2∙3×10－4is almost equal to that in LCLN steel with a C content of 0∙26％‚ and1∙7times that in HCLN steel with an N content of1∙1×10－4．However‚the size of ferrite grains in HCHN steel is about3μm‚ the smallest among the experimental steels．It is obvious that increasing deformation and N content is beneficial to the amount of fer￾rite‚and it is more effective that deformation and N are used simultaneously．According to analyses‚when the degree of deformation enlarges‚defects in non-recrystallized austenite grains increase‚which is helpful to provide plenty of nucleation sites for intragranular ferrite．While increasing the content of N to2∙3×10－4‚second-phase precipitation is promoted‚the amount of ferrite increases‚and ferrite grains are refined simultaneously． KEY WORDS microalloyed steel；hot deformation；carbon；nitrogen；intragranular ferrite 收稿日期：2008-02-27 基金项目：国家自然科学基金资助项目（No．50271009）；国际钒技术委员会（VANITEC）资助项目 作者简介：许 磊（1980－）‚男‚博士研究生；刘国权（1952－）‚男‚教授‚博士生导师‚g．liu＠ustb．edu．cn 中碳微合金非调质钢是在中碳钢基础上添加微 量合金元素 V、Ti 和 Nb 等强碳化物形成元素‚并将 变形和热处理工艺相结合的一种低合金高强度钢． 与调质钢相比‚节减了热处理工序‚避免在热处理过 第31卷 第2期 2009年 2月 北 京 科 技 大 学 学 报 Journal of University of Science and Technology Beijing Vol．31No．2 Feb．2009 DOI:10．13374／j．issn1001－053x．2009．02．020