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低屈强比钢板要求双相组织,生产控制难度大。通过发挥预矫直机的大压下量预矫作用,优化Mulpic水冷参数,改善了钢板板形及性能;优化回火温度及时间,控制组织内软硬相比例,确保了钢板各项性能及屈强比。济钢采用在线淬火+离线回火的工艺生产的油罐钢屈强比在0.90以下,一次性能合格率90%以上。 相似文献
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本文通过研究控制轧制对钢的组织和性能的影响,确定了控制轧制技术对20g钢板的适宜性。研究轧制道次及压下率对变形奥氏体的再结晶和晶粒大小的影响结果表明:热轧奥氏体晶粒是逐道细化的,但前两道轧制细化作用最大,随后道次细化作用逐渐减弱;在以20%的道次压下率轧制时,除第一、四道外,变形奥氏体都发生充分的再结晶,而在以10%的道次压下率轧制时,在所有道次中都只发生部分再结晶,20%的道次压下率要比10%为好。轧制道次及压下率对20g钢板轧后铁素体晶粒尺寸的影响规律表明:奥氏体再结晶区轧制的道次压下率及终轧温度是决定轧后铁素体晶粒大小的主要工艺参数。根据本实验结果拟定了适宜的轧制工艺参数。 相似文献
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为了提高建筑用钢的屈服强度,优化轧制工艺和降低生产成本,通过实验室轧钢并结合室温、高温拉伸试验以及扫描和透射电镜观察,研究了4种不同轧制工艺下的高强抗震耐火钢板的组织和力学性能。研究结果表明,试验用耐火钢板的组织主要由铁素体+粒状贝氏体组成。粗轧开轧温度较高时,试验用钢板的室温屈服强度和高温屈服强度都较高,粒状贝氏体的体积分数也较多。开轧和开冷温度较高时,试验钢板的高温屈服强度可以满足建筑用耐火钢板的力学性能要求。随着开冷温度的提高,试验钢板的屈服强度会进一步提高,但是组织中铁素体晶粒尺寸较大,而且塑性较差。根据冲击试验结果可以发现,随着冲击温度的降低,试验钢板的断裂吸收功下降较多。析出相分析结果表明,析出相主要是(Nb,Ti)C和(Ti,Nb,Mo)C,析出相颗粒尺寸较大。 相似文献
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Surface Ferrite Grain Refinement and Mechanical Properties of Low Carbon Steel Plates 总被引:1,自引:0,他引:1
Considering the specialities of the steel plate production, the TMCP study has been carried out with Gleeble 2000 tester to explore the possibility of fine grained ferrite in the low carbon steel plates with the chemical composition of C 0.13--0.18, Si 0.12-0.18, Mn 0.50-0. 65, P 0. 010-0. 025, and S 0. 005-0. 028. The plates with thickness of 8. 7 mm in which the ferrite grain size is smaller than 8μm have been produced by special de- formation process in the laboratory. Furthermore, the trial production of special plain carbon steel plates of 16-25 mm in thickness and 2 000- 2 800 mm in width with fine grained ferrite has been successfully carried out in the Shougang Steel Plate Rolling Plant. The ferrite grain size is 5.5-7μm in the surface layers and 9.5-15μm in the central layer respectively. The yield strength is 320- 360 MPa, tensile strength is 440-520 MPa and the elongation is 25%- 34 %. It is very important for the rolling plants to improve the low carbon steel plates' mechanical properties. The results show that the ferrite grains in the surface layer can be refined effectively by the appropriate rolling process, and the strength can be also increased. 相似文献
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系统研究了控轧及控轧控冷工艺对9.5mm薄规格X65管线钢组织和性能的影响。结果表明:控轧控冷生产的钢的强度、韧性及微观组织整体优于控轧型X65管线钢。对于控轧工艺,降低轧制温度,晶粒细化,强度提高至550MPa,屈强比有增大趋势(0.90~0.95),但韧性较差;轧后配合水冷,通过优化冷却温度和精轧开轧厚度,组织明显细化,混晶程度和带状组织均改善,强度提高至580~620MPa,-20℃冲击韧性稳定在130~150J,屈强比稳定在0.83~0.9。无论是控轧工艺还是控轧控冷工艺,仅通过降低轧制温度、冷却温度对钢的强度提高幅度有限。 相似文献
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以60mm厚Q690D高强度结构钢板为研究对象,在相同轧制条件下,系统地研究了淬火、回火温度对试验钢综合力学性能及显微组织的影响,并对第二相析出进行理论分析。试验结果表明:随淬火温度升高,试验钢强度升高,韧性下降;随回火温度升高,试验钢强度下降,但韧性明显升高。该钢采用930℃淬火(保温10min)650℃回火(保温40min)的调质热处理工艺具有良好的强韧性匹配,综合力学性能最佳,满足国标GB/T 16270—2009要求。 相似文献
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通过加压冶炼、控制轧制方式获得氮质量分数为0.59%的Mn18Cr18N钢板,研究了终轧温度对高氮奥氏体钢组织和力学性能的影响。结果表明,在再结晶区轧制并且终轧温度为970 ℃的钢板,组织为奥氏体等轴晶和部分孪晶,强度较低,塑性、冲击韧性较好;终轧温度为910 ℃的钢板,大部分组织为变形奥氏体晶粒,有少量再结晶晶粒,随着终轧温度降低钢板强度升高,塑性和冲击韧性降低;在未再结晶区轧制并且终轧温度为780 ℃的钢板,组织为变形严重的奥氏体晶粒,强度最高,塑性、韧性最低。所有试验钢有晶界析出的Cr2N相,降低终轧温度和减缓轧后冷却速度,会增加Cr2N相的析出。 相似文献
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介绍了为应对近几年来对更高强度较厚壁厚钢管的需求,日本JFE制钢公司开发的抗拉强度490~780 MPa、屈服强度385~630 MPa系列钢管产品,阐述了由于这些钢管产品都是采用高性能厚板制造,所以钢管的力学性能,尤其是屈服强度(YS)和屈服比(YR)性能更适用于建筑构架的建造。另外,根据各种设计的不同要求,JFE制钢公司通过控制制造钢管所用厚板的力学性能和制管工艺,既能制造低屈服比(YR)钢管,又能制造高屈服比(YR)钢管两种类型的建筑结构件用钢管。 相似文献
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采用室温拉伸及硬度测试研究了不同的冷变形量对316L不锈钢室温力学性能及硬度的影响,并通过OM、TEM对冷变形后组织结构的观察,分析讨论了不同变形后力学性能及硬度的变化机制.结果表明,冷变形使材料的强度和硬度得到大幅度提高,但塑性有所降低.冷变形量为25%时,钢的屈服强度可达到745 MPa,同时伸长率达到19.3%.随冷变形量的不同,该钢加工硬化能力不同.变形量低于2.5%时,强度、硬度增加的速度较快,而变形量高于约2.5%后,强度、硬度增加的速度却相对较小,其原因是变形机制不同.另外,冷变形后钢的屈服强度与硬度有着相似的变化规律,由此提出了由冷变形后硬度变化预测冷变形后拉伸屈服强度的方程. 相似文献
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轧机轧制能力不足时无法完成真正意义上的控轧控冷,设计适当的生产工艺以最大限度地提高产品力学性能十分必要。研究了控制冷却工艺对低碳钢力学性能和微观组织的影响。与空冷相比,采用控制冷却工艺进行冷却,可以提高试验钢的力学性能,减轻试验钢的带状组织。在控制冷却过程中,除开始冷却温度对试验钢的性能影响较大外,分段冷却工艺参数对试验钢性能的提高也起很大作用。结果表明:采用前段冷却为主的工艺生产的试验钢较采用后段冷却为主的工艺生产的试验钢的屈服强度提高50 MPa以上,抗拉强度提高约30 MPa,同时拥有良好的塑性和低温韧性。 相似文献
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Microstructural changes and mechanical properties with Mn-Cr steel (0.65 % C) under effect of cold rolling, rapid austenitizing, immediate oil quenching and low temperature tempering were investigated. Compared to properties of conventionally treated standard Cr-C bearing steel, higher ultimate strength, increased fracture toughness and enhanced rolling contact fatigue life were observed at comparable yield stress levels. The increased stress relaxation ability of the lath martensite matrix, and the absence of transformation microcracks, both due to the reduced carbon content in steel and also in γ-solid solution, are the main reasons of the properties' improvement. The double transfer of substructural defects from cold worked ferrite to austenite and back into martensite, and the austenite heterogeneity control, both enabled by rapid austenitizing followed by quenching, was the key for obtaining the effects mentioned. 相似文献
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《钢铁研究学报(英文版)》2016,(8):815-821
The process of “controlled rolling+relaxation+ultra fast cooling (UFC)”for high strength constructional steel with low yield ratio was presented.Microstructure and corresponding relationship with low yield ratio were in-vestigated.The results showed that the constructional steels with multiphase microstructure of bainitic ferrite,mar-tensite-austenite (M-A)and lath bainite were obtained through the creative process.The grain size decreased with the decrease in finish rolling temperature,which enhanced the strength by the grain refinement strengthening.The proper relaxation treatment promoted the bainitic ferrite lath width and the formation of blocky M-A constituent.In addition,both the tensile and yield strength increased with the decrease in finish rolling temperature and UFC final temperature,but the yield strength increased more significantly than tensile strength,which caused the increase in yield ratio.By using the process of “controlled rolling+relaxation+ultra fast cooling”,the excellent comprehensive mechanical properties of 780 MPa grade constructional steels of 12-40 mm in thickness were achieved. 相似文献