SUS304+Q235B复合板卷冷轧工艺技术研究

以SUS304+Q235B热轧复合板卷为试验材料,利用单机架冷轧可逆轧机生产线,对SUS304+Q235B复合板卷进行了冷轧轧制工艺研究,分析了SUS304+Q235B复合卷冷轧变形规律及冷轧工艺控制技术,探讨了SUS304+Q235B复合板冷轧工艺参数,制定出一套适合生产实际的工艺方案。结果表明:单机架冷轧机组生产的SUS304+Q235B复合板界面结合良好,厚度尺寸和力学性能满足用户使用要求。     

SUS301L不锈钢冷轧产品的开发

SUS301L是轨道车辆专用不锈钢,该产品生产难度大、表面要求复杂,大部分高端产品依靠进口。通过对原料化学成分控制,分析了加工硬化曲线、退火酸洗工艺和轧制工艺,制定了SUS301L产品性能控制标准,开发冷轧生产工艺。用户的使用结果以及与国内外产品的性能对比表明:生产的SUS301L冷轧产品性能、板形和表面质量与进口产品相当,完全满足国内轨道车辆行业的需求,为实现国产化打下了良好的基础。     

神经网络在冷轧301S不锈钢极薄带材表面硬度预测中的应用

 基于现场生产冷轧极薄不锈钢带材表面硬度极难控制的问题,针对301S不锈钢的冷轧生产工艺进行了研究,分析了不锈钢冷轧生产过程中影响表面硬度的相关工艺参数,得出材料的抗拉强度、轧制速度、轧制油温度和压下率是影响轧后材料表面硬度的关键因素。利用BP神经网络建立了预测表面硬度的非线性映射模型,并根据此模型得出了预测数据的趋势图谱。研究结果表明,压下率的变化对冷轧不锈钢表面硬度的调节能力最强,而其他参数对硬度的影响为10HV左右。经检验,模型的预测值和实测值的相对误差为-2.63%~2.76%,预测结果准确率高,可以用于产品质量的现场在线控制。     

探究热处理工艺对SUS301不锈钢硬度的影响

研究了热处理工艺保温的温度和时间对奥氏体不锈钢SUS301试样硬度的影响。探究试样在不同保温温度、相同保温时间下和在相同保温温度、不同的保温时间两种条件下,热处理后水冷试样硬度的变化,发现热处理温度在500℃之前,SUS301不锈钢由于在冷却过程中产生残余应力硬度会略微增加;500℃之后奥氏体不锈钢由于固溶作用,应力得以释放,硬度显著下降;热处理温度相同,增加热处理时间,SUS301不锈钢的硬度略微下降。     

SUS444不锈钢冷轧板板纹分析及工艺改进

宝钢不锈钢事业部生产的纯铁素体不锈钢SUS444,在完成冷轧、退火酸洗和精整等制造工艺后,偏厚规格成品的2B板表面会出现比较严重的板纹现象.经分析,发现原有的生产工艺不利于SUS444材料的再结晶回复,存在较多{00l}晶粒簇.通过调整热轧工艺制度和改进热处理退火工艺制度,有效改善了2 mm以上偏厚规格SUS444冷轧2B板表面的板纹质量.     

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。     

SUS304不锈钢大压下率冷轧生产

SUS304不锈钢是典型的奥氏体不锈钢,其组织为亚稳态奥氏体,在冷轧过程中易产生加工硬化,出现板形难控制、断带等一系列问题。通过比较不锈钢专用轧机的压下能力和板形控制能力,选定森吉米尔轧机为SUS304大压下轧制专用轧机。分析了原料热凸度异常(横向厚度分布异常)和轧制力波动对板形控制的影响,提出了相应的解决方案,并运用于生产实践。SUS304不锈钢的板形精度在8I之内、厚度偏差小于±3μm,与采用常规压下率无明显差异。     

冷轧工艺对奥氏体不锈钢组织性能的影响

通过对亚稳定奥氏体不锈钢SUS301L和稳定奥氏体不锈钢SUS309进行10％～70％的冷轧变形,研究了两个典型奥氏体不锈钢的组织和力学性能演变.结果表明,SUS301L不锈钢在冷轧变形过程中发生形变马氏体的转变,马氏体形核于剪切带的交叉点处,形核点的不断连接长大成为板条的形变马氏体;而SUS309通过滑移来协调塑性变形,冷变形过程中不发生马氏体转变.二者均有明显的加工硬化,即硬度和强度均随着冷轧变形量的增加而升高,延伸率表现为相反的趋势.但SUS301L是位错累积和形变马氏体转变量增加的综合作用,而SUS309仅是位错不断累积增多的结果.     

钴元素对SUS304不锈钢耐点腐蚀性能的影响

开发红土镍矿是解决镍资源危机的重点,由于红土镍矿中钴和镍伴生,导致不锈钢中钴元素的存在。本文以SUS304不锈钢钢板和电解钴为原料,采用真空感应冶炼炉和三高石墨铸模浇铸不同钴含量试样,利用线切割机加工腐蚀试样,进行三氯化铁点腐蚀试验。试验结果表明：钴元素的加入增大了铸态SUS304不锈钢点腐蚀敏感性,降低了铸态SUS304不锈钢耐点腐蚀性能,当钴含量小于0．3％时,点腐蚀速率没有增加,当钴含量为0．4％和0．5％时,点腐蚀速率明显增大。     

冷变形工艺对SUS301L不锈钢组织性能的影响

对亚稳定奥氏体不锈钢SUS301L进行了不同变形量的冷轧,并分别用X射线衍射仪和MP30铁素体测量仪测出了应变诱导马氏体及其含量.采用金相显微镜观察了试样的组织演变.研究结果表明:形变马氏体在剪切带的交叉点形核,新晶核的不断形成促使了形变马氏体的长大；形变马氏体随着冷轧压下量的增加而增加；另外,抗拉强度和硬度的增加幅度相当；平均抗拉强度与平均显微硬度的比值在2.82～3.17之间.     

Effect of a Phase Formation on Mechanical Properties of Stainless Steel SUS309L after Isothermal Aging

The effect of σ phase formation on mechanical properties, such as the tensile strength, hardness and reduction of area, of SUS 309L stainless steels with various Si content after isothermal aging was investigated. The experiments were performed using tensile and Rockwell hardness tests and scanning electron microscopy. The tensile strength of SUS 309L stainless steels with 0.17, 0.34 and 0.73 wt% Si content increased with increasing aging time from 0 to 200 h. The hardness also increased after the same aging parameters. However, the reduction of area of these materials with different Si content decreased significantly.     

退火工艺对铁素体不锈钢SUS410L热轧钢板组织和性能的影响

研究了不同退火温度和保温时间对SUS410L热轧态钢板再结晶行为和力学性能的影响。试验结果表明,当保温温度为700℃时,保温480 min后SUS410L热轧钢板仍未完成再结晶。当保温温度为750℃和800℃时分别于120 min和30 min基本完成再结晶,晶粒在之后的保温时间里逐步长大。为避免退火过程中出现马氏体而降低材料的延伸率,退火温度≤800℃。材料的力学性能与热处理后的再结晶程度密切相关。当保温温度为750℃且保温时间为480 min时可获得最佳的综合机械性能:延伸率38%,HRB硬度值67,屈服强度236 MPa,抗拉强度441 MPa。     

Thermal Scratch on Surface of SUS430 Stainless Steel Strip in Cold Rolling Process

The thermal scratch significantly influences the surface quality of the stainless steel in cold strip rolling.The thermal scratch has a close relation to the rolling parameters,the rolls surface and the emulsions used in rolling.In order to explain the thermal scratch on the strip surface,the cold rolling process of SUS430stainless steel strip was investigated in the laboratory.The thermal scratch defect occurs frequently in the second rolling pass(maximum reduction in height is 32.3%),especially on the lower surface of strips.When concentration and temperature of the emulsion are the same,the thermal scratch on the surface of the strip is aggravated with increasing the roll surface roughness.With the same roll surface roughness and emulsion concentration,the thermal scratch is obviously more severe at an emulsion temperature of 63℃than 55℃.With the same roll surface roughness and emulsion temperature,the thermal scratch is distinctly weaker at the emulsion concentration of 6%than that of 3%.     

SUS304M盘条在线固溶热处理工艺研究

研究了不锈钢紧固件用ＳＵＳ３０４Ｍ盘条的在线固溶热处理工艺,通过实验室和工业性试验结果,制定了ＳＵＳ３０４Ｍ盘要的在线固溶处理工艺,在大生产中应用,达到了预期效果。     

Great reduction pratice of SUS304 in cold-rolling

SUS304 stainless steel is typical of austenitic stainless steel,which organization is metastable austenite,easily appears work hardening in cold rolling.According to the common process,the max reduction of cold rolling in one stage is below 80%,we try to rasie the max reduction to 90%in one stage (wecalled that "great reduction" ) from the view of cuting cost.Due to the work hardening,great reduction brings lots of problem(the difficulty of flatness control,strip break..etc)。This article analyzed the great reduction from properity of SUS304 steel,mill types,flatness control,rolling technics etc,supplied the corresponding solutions,and formed a sophisticated great reduction theory. This article focuses on the unusual thermal crown of raw materials(ie,abnormal distribution of horizontal thickness) and the rolling force fluctuations in "great reduction" rolling.First,the "distortion" phenomenon which caused by unusual thermal crown of raw materials is explained,wedge-shaped strip In coiling, because of a big difference in thickness on both sides,leads to different compressive stress on both sides of flatness roll,so that the flatness measurement is distorted;Second,the "strip shifting" phenomenon caused by wedge shape of strip is explained,we analysis the stress on both sides of the strip,concluded that the wedge-shaped strip on the coiler will shift to the thick side of the deviation,the amount of strip shifting is related to the wedge level;Because of the characteristics of SUS304,the strip is difficult to be rolled in the last few passes.so the strip breaking is easily occurred,we found the reasonable parameters(rolling speed, cooling oil,tension,etc) to solute that problem;The deviation of rolling force will cause the shape of the roll gap,thus affecting the shape control,especially in the head and tail part of the strip,It is important to minimize the deviation of rolling force;The "great reduction" process provide the favorable flatness(< 8I-unit) and thickness deviation which less than±3 um,with no significant difference between common process.In mechanical properties,the elongation of the great reduction strip is less than common products by 2%-3%,but that can be adjusted through the annealing process improvement.At present,we have been using this technology for mass production,achieving good economic benefits.     

SUS430不锈钢夹杂物的变化规律研究

对采用EAF-AOD-LF-CC工艺路线生产SUS430不锈钢炼钢过程夹杂物的成分组成和形貌、尺寸变化进行了分析,结果表明,SUS430不锈钢中主要形成呈球状或不规则球状分布的硅酸盐复合夹杂物,其变形能力较差。随着LF精炼和连铸过程的进行,SUS430不锈钢钢水中夹杂物的平均直径呈逐渐减小的趋势,铸坯夹杂物的平均直径为3.4μm左右,5μm以上的夹杂物占夹杂物总数的1%以下。变形能力较差的硅酸盐夹杂和镁铝尖晶石夹杂是引起SUS430不锈钢冷轧板表面线鳞缺陷的重要原因,采用钙处理和复合脱氧工艺,对改善SUS430不锈钢冷轧板的表面线鳞缺陷有利。     

SUS410S铁素体不锈钢焊接性能研究

在不锈钢加工工艺中,焊接是最主要的必不可少的加工技术之一。本文以SUS410S铁素体不锈钢为原料,采用手工钨极氩弧焊方法,选用日本生产的交直流氩弧焊机,以ER30gL焊丝为焊接填充金属材料。研究其焊接性能。试验结果表明：在选定的焊接工艺参数条件下,焊接接头性能满足要求;无损检测焊接接头内不存在裂纹、未熔合、未焊透和条形缺陷,抗拉强度、面弯和背弯弯曲检验结果良好,宏观检查受检面焊缝均未发现任何焊接缺陷,耐晶间腐蚀试验未发现明显的裂纹,焊缝为细长的条状奥氏体加少量的8铁素体组织,热影响区为铁素体加马氏体组织。