·试验研究·

X70含钒管线钢冷却工艺对组织和性能的影响

郑玉申1文小明2

(1. 北京隆盛泰科石油管科技有限公司陕西西安710077;

2. 本溪钢铁(集团)有限责任公司辽宁本溪117000)

摘要：对于添加Nb-V复合微合金的X70管线钢，通过控制轧制冷却工艺获得不同的微观组织和性能，对其进行对比研究分析，解释说明X70含钒管线钢冷却工艺、组织和性能关系。结果表明，当冷却速率减小情况下，管线钢组织转变为多边形铁素体和准多边形铁素体为主，同时还有一定数量的退化珠光体，强度略有降低，而塑性提高。在相同冷却工艺条件下，随着卷取温度的降低，管线钢组织由粒状贝氏体为主，转变为板条形貌特征的贝氏体铁素体为主，M-A组元也随着卷取温度的降低而减少且细化。此外，卷取温度较高情况下，管线钢强度异常增加可能与钢中V的析出有关。

关键词：管线钢；冷却工艺；组织；力学性能

作者简介：第一郑玉申，男，1969年生，工程师，1992年毕业于中国石油大学矿业机械专业，主要从事油气输送钢管驻厂监造工作。E-mail:zhengyushen@cnpc.com.cn

文章编号：中图法分类号：TG142.1

收稿日期：(2014-04-30编辑：屈忆欣)

Effect of Cooling Process on Microstructure and Mechanical Properties of Vanadium-Bearing X70 Pipeline SteelZHENG Yushen1WEN Xiaoming2

(1.BeijingLongshineOilTubularTechnologyCo.Ltd.,Xi’an,Shaanxi710077,China;

2.BenXiIronandSteel(Group)Co.Ltd，Benxi,Liaoning117000,China)

Abstract：Different microstructure and mechanical properties would be produced by taking control of rolling and cooling process of Nb-V microalloyed X70 pipeline steel.Then explain the relations between the cooling process and microstructure and mechanical properties by comparatively research and analysis. The results show that, when the case of the cooling rate decreases, the pipeline organization turns into polygonal ferrite and quasi-polygonal ferrite-based, as well as the degradation of a certain number of pearlite, strength is slightly decreases, while the plasticity increases. In the same cooling process conditions, with the curl temperature reduces, the main pipeline steel organization turns from granular bainite into bainitic ferrite of lath morphology, MA component is also reduced and refined as the curl temperature decreases. In addition, when the the curl temperature is higher, pipeline steel strength abnormal increases may be related to the precipitation of steel V.

Key word： pipeline steel,cooling process, organization, mechanical properties

0引言

随着对石油和天热气能源需求的不断增长，越来越多地采用管道输送这种最经济快捷的运输方式[1]。为提高输送效益，管线工程向着大管径、高压方向发展[2]。进而对管线钢的强度、低温韧性、焊接性等综合性能的要求也越来越高[3]。目前，X70钢级管线钢多采用通过添加铌、钒、钛等微合金元素进行微合金化，并结合TMCP工艺生产，以获得优良组织，使其在较低的碳当量下具有较高的强度和韧性等综合力学性能。……