热轧低碳带钢实物质量分析与提升

针对低碳Q195窄带钢在冷轧中出现起皮、麻点等质量问题,基于生产实践设计了专门的铸坯表面、低倍及带钢表面酸洗跟踪试验,通过成分、金相、裂纹、夹杂以及扫描电镜分析,认为造成带钢表面质量缺陷的因素一是铸坯内部的裂纹、夹渣、皮下气泡、结疤等缺陷,二是铸坯加热和除鳞效果不力,造成表面氧化铁皮的压入。此外,S含量高也是造成铸坯缺陷进而影响带钢质量的因素之一。为此,结合生产实际,从冶炼和轧制两个工序采取了相应的改进措施,改进后带钢表面缺陷率由15.75％降到了2.22％。     

非精炼生产Q195带钢表面缺陷的分析及控制

采用扫描电镜结合能谱仪,分析了Q195带钢表面缺陷产生的原因,通过优化Q195钢连铸二冷配水制度、直上工艺钢中氧含量控制及延长静搅时间等措施,Q195冷轧带钢鳞片状缺陷及线状起皮缺陷得以消除。     

提高Q195热轧带钢塑性生产工艺实践

天津市新天钢联合特钢有限公司在生产Q195热轧带钢过程中,发现部分批次热轧带钢在后续冷轧加工过程中存在强度偏高、塑性较低的情况,给下游冷轧、酸洗用户带来了一定的影响。本文介绍了热轧带钢塑性指标对后续冷轧工序所产生的影响,从现行生产工艺流程出发,分析了影响热轧带钢塑性指标的主要因素,确定了造成Q195热轧带钢塑性较低的主要原因,并提出了优化改进措施。通过优化加热工艺、增加中间辊道保温装置、优化卷取工艺,提升了Q195热轧带钢塑性,获得了下游冷轧加工用户的认可。     

带钢起皮成因分析及改进

针对某厂Q195冷轧镀锌带钢起皮缺陷,应用金相显微镜、大样电解、扫描电镜及能谱分析对冶炼过程中各工序钢水内的大型夹杂物及显微夹杂物进行分析。结果表明,冷轧缺陷主要是由于钢包卷渣和钢包耐火材料剥落所致。通过优化生产工艺及调整钢包浇注料材质等措施,基本消除了冷轧带钢表面起皮和镀锌挂渣缺陷,提高了镀锌板表面光洁度。     

唐山建龙Q195L带钢起皮缺陷分析

对Q195L带钢起皮处的形貌、成分进行了分析，认为形成缺陷的主要原因是夹杂物、夹渣等，应从冶炼、加热、除鳞和轧辊的工作状态等方面解决这个问题。     

SUS430黄色脏污缺陷分析与工艺控制

采用电子显微镜与能谱分析对SUS430带钢表面的黄色脏污缺陷进行分析和研究,结果表明:SUS430冷轧带钢表面的黄色脏污缺陷主要是由于生产机组电解段除鳞能力不足,部分氧化铁皮残留在带钢表面造成。通过修订生产机组Na_2SO_4电解工艺参数、提高脱脂及刷洗能力等措施,SUS430冷轧带钢表面的黄色脏污缺陷得到了消除。     

冷轧基料表面麻坑缺陷分析及应对措施

分析了唐山市德龙钢铁有限公司650生产线热轧带钢表面麻坑缺陷的产生原因,从产生机理入手,通过调整加热工艺、优化除鳞设备、合理分配轧机负荷、控制冷却方式、编排生产计划等措施,带钢表面麻坑缺陷由28%降低到9%,在保证物理性能不变的同时,氧化铁皮厚度由12.1%降低到8.6%,不仅提高了带钢的产品质量,还满足了终端客户对冷轧基料的使用要求。     

热轧窄带钢Q195通条重皮缺陷成因分析与改进

针对某钢厂的Q195窄带钢在用于冷轧薄带生产过程中出现较多的重皮缺陷问题,对缺陷试样进行了分析,确定了冶炼过程中脱氧不充分和全氧含量过高为缺陷产生的主要原因。通过优化冶炼工艺,缺陷发生率由80%左右降到3%以下。     

莱钢低碳窄带钢质量缺陷的研究与改进

根据莱钢低碳Q195窄带铜在冷轧中出现起皮、麻点等质量问题，基于生产实践安排了专门的铸坯表面、低倍、带钢表面酸洗跟踪试验，通过成分、金相、裂纹、夹杂以及扫描电镜分析，对影响带钢表面质量的问题进行了深入探讨，在此基础上，系统分析了从冶炼到轧制过程中的工艺参数的适合性。基于生产实践工艺备件并结合研究分析结果，制定了工艺改进措施，促进了低碳Q195窄带钢的综合实物质量的提升。     

低成本生产优质带钢表面缺陷分析及控制

采用电镜结合能谱对表面缺陷进行分析得出,缺陷因连铸坯表面缺陷所致,鳞片状缺陷源于坯壳出结晶器后,铸坯受到不均匀冷却产生鼓肚,在矫直过程中形成褶皱缺陷。通过对低成本工艺生产Q195热轧带钢缺陷的分析提出相应的优化措施,提高连铸坯质量。     

Q345B热轧板板面结疤缺陷产生原因分析

采用微观组织分析法, 对某钢铁公司生产的Q345B热轧板板面结疤缺陷的成因进行了分析。结果表明,该类热轧板的结疤缺陷是由于连铸工艺出现异常,造成板面或近表层卷渣、微裂纹和气泡等板坯缺陷,并在连铸过程中裂纹出现了高温氧化行为,在加热炉中裂纹发生二次氧化、脱碳、晶界弱氧化等行为,在后续轧制过程中进一步恶化板面,从而造成了板面大面积结疤产生。     

Q195冷轧用钢生产工艺研究

冷轧用钢要求热轧薄板的屈服比低、强度低、塑性好、变形能力强、表面质量好。研究了Q195钢高温塑性规律、连续冷却相变规律、高温奥氏体热变形行为,分析了化学成分、轧制工艺参数对Q195钢的影响,给出了合理的化学成分范围。建议采用＂三高一低＂的热轧工艺,即高温加热（1 180～1 250℃）、高温开轧（大于1 100℃）、高温终轧（870～850℃）和低温卷取（610～640℃）,可保证Q195冷轧用钢获得良好性能。     

Augmentation in chemosensitivity of intratumor quiescent cells by combined treatment with nicotinamide and mild hyperthermia

C3H/He and Balb/c mice bearing SCC VII and EMT6/KU tumors, respectively, received continuous administration of 5-bromo-2'-deoxyuridine (BrdU) for 5 days using implanted mini-osmotic pumps to label all proliferating (P) cells. Nicotinamide was administered intraperitoneally before cisplatin injection and/or tumors were locally heated at 40 degrees C for 60 min immediately after cisplatin injection. The tumors were then excised, minced and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis-blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (quiescent (Q) cells) was determined using immunofluorescence staining for BrdU. The MN frequency in total (P+Q) tumor cells was determined from tumors that had not been pretreated with BrdU labeling. The sensitivity to cisplatin was evaluated in terms of the frequency of induced micronuclei in binuclear tumor cells (MN frequency). In both tumor systems, the MN frequency in Q cells was lower than that in the total cell population. Nicotinamide treatment elevated the MN frequency in total SCC VII cells. Mild heating raised the MN frequency more markedly in Q cells than in total cells. The combination of nicotinamide and mild heat treatment increased the MN frequency more markedly than either treatment alone. In total SCC VII cells, nicotinamide increased 195mPt-cisplatin uptake. Mild heating elevated 195mPt-cisplatin uptake in total EMT6/KU cells. Cisplatin-sensitivity of Q cells was lower than that of total cells in both tumor systems. Nicotinamide sensitized tumor cells including a large acutely hypoxic fraction, such as those of SCC VII tumors, through inhibition of the fluctuations in tumor blood flow. Tumor cells including a large chronically hypoxic fraction such as Q cells were thought to be sensitized by mild heating through an increase in tumor blood flow.     

直装加热过程连铸坯应力场分析

热轧含Nb低合金Q345C钢在热送工艺中受到应力作用产生表面缺陷,轧制的钢卷中部出现线状和疤状缺陷,分析发现缺陷卷的入炉温度集中在600℃以上。裂纹产生的主要原因是连铸坯热装加热过程中受到热应力和相变应力的综合作用,当铸坯的抗拉强度和塑性不足以抵抗拉应力时,其表面就会开裂。利用计算机模拟与现场实验相结合的方法研究连铸坯...     

Researches on the problems in the production of low nickel austenitic stainless steel

Problems encountered in the production of low nickel austenitic stainless steel have been studied. These problems primarily include the changes to the microstructure of the slab during the heating process,the formation and removal of deformation- induced martensite during cold rolling,and the effects of the annealing process on the surface oxide structure. A reasonable manufacturing process has been proposed on the basis of the research results and highquality cold-rolled strips of low nickel austenitic stainless steel have been produced.     

Formation of Phosphorous Surface Inverse Segregation in Twin-Roll Cast Strips of Low-Carbon Steels

 The formation of phosphorous surface inverse segregation (SIS) in twin-roll cast strips of low-carbon steels was studied. High phosphorous strips were fabricated by using a pilot twin-roll strip caster and a melt/substrate contacting apparatus, respectively. Solidification structures of strips were observed and analyzed, and phosphorus distributions along longitudinal sections of strips were investigated and discussed. The results showed that solidification structures of all strips were columnar grains, either integrated or coarse in the strip made by the melt/substrate contacting apparatus or damaged in some degree in cast strips; and that during cast strip solidification, enrichment of phosphorus occurred between columnar grains, and the average phosphorus concentration near the surface in the strip with 015% of phosphorus was measured to be about 027% which was obviously higher than that in the bulk.     

SPHC板带除鳞工艺实践与改善

基于热轧线的工况特点，从板带除鳞机理着手研究了氧化铁皮的去除工艺。结果表明，通过优化加热工艺和加热制度，SPHCCP生氧化铁皮压入的问题得到有效改善。