共查询到20条相似文献,搜索用时 93 毫秒
1.
采用光学显微镜、扫描电镜及力学性能实验等研究了控轧控冷工艺对X70级管线钢的组织与力学性能的影响。结果表明:不同终轧温度下X70管线钢的显微组织主要由多边形铁素体、贝氏体和少量的珠光体组成,且随着终轧温度的升高,抗拉强度与屈服强度降低,硬度下降,冲击韧性提高,但屈强比变化不大,并且落锤性能较差;随着终轧温度的升高,晶粒尺寸逐渐增大,铁素体体积含量增多。在不同的终冷温度下,X70管线钢的显微组织主要由多边形铁素体和贝氏体组成,并且随着终冷温度的升高,抗拉强度大幅度降低,屈服强度则呈M形波动,硬度呈线性降低,冲击吸收能量大幅度升高且落锤性能较好,屈强比缓慢升高;随着终冷温度的升高,晶粒度等级基本保持稳定,铁素体含量呈线性增加。该大变形管线钢最优的轧制工艺为控制终轧温度为840℃,终冷温度为450℃。 相似文献
2.
通过热模拟实验, 研究了加热温度、变形温度、变形量、冷却速率和卷取温度对高Nb含量管线钢钢板组织性能的影响, 并确定了工业生产方案。工业试制结果表明: 在1 170~1 200 ℃进行加热保温, 粗轧温度控制在1 020 ℃以上, 变形量控制在30%以上, 精轧入口温度不大于950 ℃, 终轧温度控制在(800±20) ℃, 冷却速率控制在10~30 ℃/s, 卷取温度控制在500~530 ℃, 生产的高Nb含量X80管线钢钢板组织为均匀的针状铁素体, 力学性能优良, ?20、?40 ℃低温冲击功均达到300 J以上, ?15 ℃落锤撕裂试样的剪切面积达到97%以上。 相似文献
3.
4.
对试制的X80级抗大变形管线钢不同开始冷却温度下的力学性能进行了测试,并通过扫描电镜分析了不同开始冷却温度下钢板最终组织及形态,研究了控轧控冷工艺对X80级抗大变形管线钢组织与性能的影响.结果表明,随着钢板开始冷却温度的降低,X80级管线钢中的先共析铁素体量逐渐增加,贝氏体含量逐渐降低,钢板抗大变形性能参数提高.当开始冷却温度在740 ℃时,钢板具有最佳的综合力学性能,其屈服强度Rt0.5为565 MPa,抗拉强度Rm为730 MPa,伸长率A为42.7%,屈强比Rt0.5/Rm为0.75,Rt1.5/Rt0.5为1.181,Rt2.0/Rt1.0为1.116,均匀变形伸长率达到12.33%,具有较强的抗变形能力. 相似文献
5.
针对海洋石油工业的发展趋势,以海洋用高钢级X80管线钢为研究对象,采用焊接工艺试验、力学性能测试及显微分析技术,研究了焊条电弧焊工艺下X80管线钢焊接接头的性能和热影响区的组织变化规律.结果表明:采用设计的焊条电弧焊工艺参数对海洋用X80管线钢进行焊接,可以得到合格的焊接接头.X80管线钢母材和焊接接头所具有的针状铁素... 相似文献
6.
7.
8.
9.
10.
11.
12.
运用Gleeble-1500D热模拟实验机模拟了X100管线钢的轧制过程,并且通过Leica MEF-4M型金相显微镜、HITACHIS-4500型扫描电镜和显微硬度计研究了不同工艺下实验钢的显微组织和力学性能的变化规律。结果表明:X100管线钢主要由粒状贝氏体和板条贝氏体组成。降低精轧变形量、终冷温度和弛豫时间,实验钢的显微组织中板条贝氏体含量增多,显微硬度增加。通过粒状贝氏体组织的细化就可以获得很高的硬度值(300 HV),所换算的强度远远大于700 MPa。说明通过粒状贝氏体的控制获得X100管线钢的强度是可行的。 相似文献
13.
14.
郑宏伟 《热处理技术与装备》2016,(6):49-52
通过金相分析、扫描电镜和硬度分析,研究了X80管线钢试样的抗HIC性能。结果表明:X80管线钢中裂纹不是由夹杂物引起的,而是由Mn、P偏析生成了对HIC特别敏感的硬显微带组织;HIC裂纹在准多边形铁素体形核,向外扩展,终止于板条状铁素体。准多边形铁素体的抗HIC性能劣于板条状铁素体,板条状铁素体对裂纹的扩展有明显的阻止作用。 相似文献
15.
16.
In order to explore the eff ect of a small amount of rare earth addition in ultra-cleaned pipeline steel and the influence of the cooling process on the tensile and impact properties, three API X80 pipeline steels were fabricated by varying RE addition and the cooling process at the same time. Three microstructures with different features for a low C high Nb microalloyed high-strength pipeline steel and the corresponding mechanical properties were investigated. The results showed that even in the ultra-cleaned steel with O and S contents less than 10 ppm, the addition of RE would still cause an increase in the volume fraction of inclusions consisting of complicated RE oxysulfide and RE sulfide. More inclusions formed in the 112 ppm RE steel were harmful to the low temperature toughness, while few inclusions formed in the 47 ppm RE steel had almost no influence on the low temperature toughness. The two RE additions had no effect on strength of the steels. As the finishing cooling temperature was increased and the cooling rate was decreased within a certain range, the volume fractions of polygonal ferrite and quasi-polygonal ferrite as well as the number density and size of martensite–austenite islands were increased. Under such combined effect, the strength of the steels had almost no change. As the finishing cooling temperature was increased from 481 to 584 ℃ and the cooling rate was reduced from 20 to 13 ℃/s, for the steel with 112 ppm addition of RE, there was an obvious decrease in the low temperature toughness. The reduced value(about 33 J) of the USE of steel consisted of two parts including the influence(about 18 J) of more inclusions formed due to 112 ppm addition of RE and the eff ect(about 15 J) of the lower high-angle grain boundaries. 相似文献
17.
Liu Chengjun Liu Hongliang Jiang Maofa Northeastern University Shengyang China 《稀有金属材料与工程》2011,(Z3):51-55
The studies of the rare earth elements (RE) in low carbon steels suggest that the RE inhibits the ferrite transformation, which is the same effect as Mo alloying in pipeline steels. The purpose of this work is to discuss the relationships between the RE microalloying and the microstructure in pipeline steels. The X80 pipeline steels with different RE and Mo additions have been produced by vacuum induction furnace. The Gleeble-2000 thermal simulator, optical microscopy, and scanning electron microscopy with EBSD have been used. The continuous cooling transformation (CCT) curve was obtained and analyzed, combined with the study of microstructure. The results indicate that the microstructure of thermal simulator test metal is characteristic of quasi-polygonal ferrite and bainite, and trace RE could significantly inhibit the transformation of quasi-polygonal ferrite. The 0.0040wt% content of RE plays the same role as 0.1 wt% content of Mo alloying in pipeline steels. What’s more, the fine bainite grained structure is obtained with RE microalloying. Theoretically RE could be employed in pipeline steels as microalloying, and a partial substitution of Mo by RE is possible. 相似文献
18.
19.