共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
采用直弧型连铸机生产厚180mm、200mm;宽1030mm、1240mm的410S板坯,铸坯出现横裂缺陷率平均为6.75%。本文就横裂形成的原因进行了分析,提出了工艺控制措施,杜绝了横裂缺陷。 相似文献
3.
通过对横裂的铸坯生产情况的调查研究和取样分析,确定了热连轧硅钢铸坯横裂是由于铸坯内部裂纹在后序加热、轧制过程中扩展并暴露出表面而形成的,并提出了防止铸坯横裂的办法。 相似文献
4.
5.
6.
就0Cr13不锈钢连铸板坯表面横裂形成的原因进行了分析,提出了相应的工艺控制措施,从而杜绝了横裂的产生。 相似文献
7.
本文主要探讨了双辊薄带连铸带坯边部横裂的形成原因,认为由于边沿毛刺严重,增加出带阻力,导致拖带张管力增加,使毛刺首无产生开裂,继而扩大到基板,形成横裂。 相似文献
8.
9.
针对石钢公司300mm×360mm大断面GC r15轴承钢连铸坯加热出现横裂缺陷,并在轧制后形成"巢穴"状孔洞的问题,分析了缺陷试样的组织和连铸坯的加热过程,认为加热速度过快以及各区域之间的温升梯度太大是连铸坯发生横裂的主要原因。通过优化加热制度,使连铸坯的横裂由20.11%降低至0.35%以下。 相似文献
10.
11.
济钢中厚板厂投产调试以来,在轧制厚度32~50 mmQ345B过程中,钢板边部裂纹频繁发生,成为影响钢板质量的重要因素。通过对厚板边裂的金相分析和对比试验,发现连铸坯的角部横向裂纹(角横裂)是钢板边裂缺陷的起源。结合济钢新建厚板连铸机的生产情况,分析了板坯角横裂的形成原因,根据实际工艺条件,采取针对性的措施后,钢板表面边裂的发生率大幅度降低。 相似文献
12.
JIANG Zhenyi XIE Haibo WEI Dongbin School of Mechanical Materials Mechatronic Engineering University of Wollongong Wollongong NSW Australia 《Baosteel Technical Research》2010,(Z1)
In this paper,the mechanics of strip edge cracks and its propagation has been studied,and the effects of strip edge drop and stress intensity factor(SIF) on edge crack defections during cold rolling of thin strip have been discussed.An experimental investigation was presented into the effect of strip edge drop on edge cracks during cold rolling of thin strip.The edge crack increases significantly due to more inhomogeneous deformation and work hardening at the strip edge.The effective stress intensity fac... 相似文献
13.
Haibo Xie Zhengyi Jiang W. Y. Daniel Yuen 《Metallurgical and Materials Transactions B》2011,42(6):1244-1252
Edge cracks in cold rolling of the thin strip affect the strip quality and productivity significantly. In this study, an experimental
and mechanical investigation on microstructures has been carried out to study the edge crack formation during cold rolling
of the thin strip. The effects of the feed material microstructures on the edge crack evolution were studied employing optical
microscopy and scanning electron microscopy (SEM). Experimental observation indicates that fine grain occurs in hot-rolled
microstructure and coarse grain is produced in ferritic rolled microstructure. Different grain sizes affect significantly
the formation mechanics of the microcrack, crack initiation, and orientation of crack extension. The grain size and grain
boundaries effects on crack retardation are discussed also during edge crack initiation. During the crack growth in coarse
grain, most edge crack tips will blunt, which improves the crack toughness by causing less stress concentration. Overall,
the fine microstructure shows a good crack initiation resistance, whereas the coarse microstructure has a better resistance
to crack propagation. This research provides additional understanding of the mechanism of microstructure influence on edge
crack evolution of cold strip rolling, which could be helpful for developing defect-free thin strip. 相似文献
14.
通过金相显微镜和扫描电镜等分析手段,对新钢厚规格Q460D钢板的表面微裂纹和边裂进行分析,确定连铸过程中保护渣卷入钢坯表皮下是边裂产生的主要原因,晶界处Cu是产生表面网状微裂纹的主要原因. 相似文献
15.
汽车用超高强度双相钢CR550/980DP冷轧边裂问题,严重影响热轧/冷轧工序界面生产顺行,易造成冷轧机架间及连退炉内断带事故,成为超高强度双相钢生产的难题。基于高温热塑性曲线和热轧动态CCT曲线,采用对显微组织、力学性能、裂纹扩展分析等手段明确冷轧边裂产生原因。试验结果分别指出,精轧阶段带钢横向温度分布不均匀、边部温降大,导致在第Ⅲ脆性区轧制;同时,受Nb作用再结晶温度提高,边部低温区为未再结晶区轧制;当应变量超过塑性极限、轧制力超过边部热强度时,形成热轧卷边裂。边部形成细小弥散的铁素体(F)和马氏体(M)两相组织,不协调应变将导致F/M相界面产生应力集中而形成裂纹;裂纹以微孔聚集方式进行扩展,形成热轧卷无边裂-冷轧边裂现象。通过投用边部加热器和优化初轧定宽量、精轧入口温度、精轧机架间冷却水、终轧温度、卷取温度等措施,实现热轧卷边部质量改善、解决边裂问题。 相似文献
16.
《Acta Metallurgica》1987,35(6):1333-1341
The cracking and spalling processes that accompany the edge loading of brittle plates have been investigated. Experiments performed on glass and on PMMA have revealed systematic trends in crack location, crack propagation load, and in the onset of spalling. In particular, a steady state crack growth region has been identified wherein the cracks propagate parallel to the side surface. Calculations of mode I and mode II stress intensities have allowed comparison of the crack trajectories and crack propagation loads with experimental measurements. The general trends in cracking were found to be broadly consistent with predicted behavior governed by a zero mode II criterion and assuming that the cracks grow into a steady state trajectory. However, some quantitative discrepancies exist. These have been attributed to constraining tractions that develop upon distortion of the test specimens. 相似文献
17.
汽车用超高强度双相钢CR550/980DP冷轧边裂问题,严重影响热轧/冷轧工序界面生产顺行,易造成冷轧机架间及连退炉内断带事故,成为超高强度双相钢生产的难题。基于高温热塑性曲线和热轧动态CCT曲线,采用对显微组织、力学性能、裂纹扩展分析等手段明确冷轧边裂产生原因。试验结果分别指出,精轧阶段带钢横向温度分布不均匀、边部温降大,导致在第Ⅲ脆性区轧制;同时,受Nb作用再结晶温度提高,边部低温区为未再结晶区轧制;当应变量超过塑性极限、轧制力超过边部热强度时,形成热轧卷边裂。边部形成细小弥散的铁素体(F)和马氏体(M)两相组织,不协调应变将导致F/M相界面产生应力集中而形成裂纹;裂纹以微孔聚集方式进行扩展,形成热轧卷无边裂-冷轧边裂现象。通过投用边部加热器和优化初轧定宽量、精轧入口温度、精轧机架间冷却水、终轧温度、卷取温度等措施,实现热轧卷边部质量改善、解决边裂问题。 相似文献
18.
19.
珠钢热轧板卷边裂缺陷的工艺浅析 总被引:1,自引:1,他引:0
本文针对今年第一季度珠钢热轧板卷出现的边裂缺陷进行调整统计,并选取了一些关键工序的相关工艺参数进行对比分析,试图找出造成边裂缺陷的主要原因和影响的规律。 相似文献
20.
通过对板坯边部纵裂纹缺陷产生的原因进行仔细调查分析,找出了其主要原因是结晶器铜板冷却水缝布置不合理造成.通过重新优化结晶器铜板冷却水缝,完善部分工艺参数后,有效地消除了铸坯边部纵裂纹缺陷. 相似文献