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1.
张志慧  贾小华 《河北冶金》2023,(12):46-49+55
通过扫描电子显微镜、光学显微镜等对X60级管线钢显微组织与冲击试样断口形貌进行观察分析,研究了控轧控冷工艺对试验钢的热轧显微组织及低温冲击韧性的影响。结果表明:试验钢控轧控冷条件下冲击断口无明显裂纹源,基本呈现等轴韧窝形貌特征;其获得的针状铁素体组织较常规轧制下多边形铁素体组织更加细化、均匀,晶粒尺寸均值由20μm下降至8μm左右,其尺寸小于2μm的占比达75%以上;控轧控冷工艺较常规轧制试验钢具有更好的强度及塑韧性,尤其-10℃冲击功达到180 J以上。在生产过程中通过合理设定机架间冷却水强降温工艺与轧后层流冷却速率及卷取温度控制,实现精轧控制轧制与层流控制冷却相结合的控制工艺,可极大地改善超厚规格X60管线钢低温冲击性能。  相似文献   

2.
通过控轧控冷试验,力学性能检验和组织的光学显微观察,研究了温度参数对铌微合金钢组织性能的影响。结果表明:两阶段控轧及控冷所获晶粒尺寸明显小于常规轧制+快速冷却的晶粒尺寸;随冷却速率的增大或终冷温度的降低或精轧开轧温度的降低,试验钢晶粒细化,混晶程度加重,强度增大,塑性降低;精轧低温开轧利于韧性提高;铁素体混晶可能源于因铸坯中Nb(C,N)的不均匀分布造成的原始奥氏体混晶,粗轧大压缩比轧制可以消除这种混晶现象。  相似文献   

3.
李文卿  王轶文 《钢铁》1992,27(4):46-50
对微合金化中碳钢进行了控制轧制和控制冷却的试验;测定了各项力学性能及先共析铁素体最f_α、铁素体平均截线长度d_α、铁素体平均自由程λ_α和珠光体平均片层间距S_(oj),采用数理统计的方法研究了控轧控冷微合金化中碳钢力学性能与组织参量间的关系,对力学性能非线性回归方程的幂指数做了优化,得到优化的定量关系式;探讨了控轧控冷中碳钢的强韧化机制。  相似文献   

4.
罗永恒  何涛 《宽厚板》2022,(3):23-25+38
基于柳钢中厚板生产线超快速冷却改造项目,采用低碳、适当微合金化的成分设计和3种不同控轧控冷工艺,进行X70级管线钢的控轧控冷工艺开发试验。结果表明:在轧制温度相同的情况下,随着返红温度的降低,X70级管线钢的显微组织更加有利于针状铁素体的形成,钢板落锤撕裂韧性逐渐提高,具备最佳的综合力学性能,满足相关技术标准要求。  相似文献   

5.
控轧控冷HRB400钢筋位错强化效果定量研究   总被引:2,自引:0,他引:2  
通过JEOL-2100扫描电镜观测控轧控冷HRB400钢筋和常规轧制的钢筋试样中位错的衍衬形态,建立位错密度测量模型,计算位错密度值;定量衡量控轧控冷HRB400钢筋中位错对强度的贡献,研究位错强化机理,揭示强度与位错密度的关系。结果表明,控轧控冷HRB400钢筋中位错强化作用明显优于常规轧制的钢筋。  相似文献   

6.
吴迪  李壮  吕伟 《钢铁》2012,47(8):36-38,40,42
通过实验室热轧机组的控轧控冷试验,研究了控轧控冷参数对超高强铁素体/贝氏体双相钢组织性能的影响。结果表明,采用不同温度终轧,轧后不同方式冷却,抗拉强度几乎都在1 000MPa以上,屈强比在0.54~0.62之间,伸长率在13%~17%之间。铁素体晶粒随终轧温度降低和冷却速度加快而细化;终冷温度降低,贝氏体量增多。经800℃终轧后层流冷却至560℃左右空冷,由于铁素体晶粒细化,组织中大量的粒状贝氏体、无碳化物贝氏体、少量的孪晶马氏体以及残余奥氏体的存在使抗拉强度达1 130MPa,伸长率达16%,强塑积达到18 080MPa.%的最高值。控轧控冷获得以铁素体/贝氏体双相组织为主并含有少量残余奥氏体+马氏体的复相组织,使试验钢具有了优异的力学性能。  相似文献   

7.
试验钢SCM435(/%:0.33~0.38C,0.15~0.35Si,0.60~0.85Mn,≤0.025P,≤0.025S,0.90~1.20Cr,0.15~0.30Mo)盘条的生产流程为80t BOF-LF-280 mm×325 mm铸坯-160 mm×160 mm热轧坯-热连轧成Φ16 mm盘条。试验研究了160 mm×160 mm热轧坯由常规轧制工艺(开轧1060℃,精轧930~950℃,吐丝860~900℃,冷却速度0.5~0.6℃/s)和控轧控冷工艺(开轧1060℃,精轧820~850℃,吐丝780~820℃,冷却速度0.4~0.5℃/s)对SCM435钢热轧盘条组织和力学性能的影响。结果表明,随着精轧温度的降低和冷却速度的减小,钢热轧盘条的组织得到改善,抗拉强度明显降低;常规工艺轧制SCM435钢热轧盘条的抗拉强度平均952 MPa,组织为铁素体+珠光体+贝氏体+马氏体,控轧控冷工艺轧制的SCM435钢热轧盘条的抗拉强度平均817 MPa,组织为均匀的铁素体+珠光体。结合控轧控冷工艺原理对钢的组织和性能变化进行了分析。  相似文献   

8.
基于热力模拟实验及相变实验,设计了钒微合金化MG700高强锚杆钢的合理控制轧制及控制冷却工艺,具体为:采用970~1 050℃进行粗中轧、800~840℃进行精轧的控制轧制工艺,以及采用中轧和精轧之间穿水冷却,控制终冷温度820~850℃、精轧后空冷的控制冷却工艺。上述控轧控冷工艺工业试生产结果表明,MG700锚杆钢的屈服强度稳定为720~760 MPa,抗拉强度稳定为885~925 MPa,断后延伸率稳定为17.5%~19.0%,综合力学性能优良。MG700锚杆钢的微观组织以铁素体和珠光体为主,铁素体晶粒直径介于0.60~13.64μm之间,平均直径约为3.86μm。研发的新型MG700高强锚杆钢力学性能及微观组织特征满足煤炭行业锚杆用钢的相关标准,可为同类产品的开发提供理论支撑和实践经验。  相似文献   

9.
对不同碳、硅、锰含量的16Mn钢板进行了控制轧制和控制冷却试验;测定了控轧控冷工艺参数、力学性能、铁素体晶粒平均直径和珠光体百分数,通过多元线性逐步回归分析得到多元线性回归方程,用以解决16Mn钢板控轧控冷生产中的一些实际问题。  相似文献   

10.
通过热轧试验研究了两阶段轧制+层流冷却、空冷、超快冷的TMCP工艺对高硅铌钢、高硅Nb-Ti钢、低硅Nb-Ti钢显微组织和力学性能的影响。结果表明,控轧控冷后的试验钢含有铁素体、贝氏体、马氏体以及少量残余奥氏体的混合组织。在控轧控冷工艺参数相近的情况下,高硅铌钢、高硅Nb-Ti钢、低硅Nb-Ti钢的抗拉强度依次减小,其伸长率和强塑积依次增大。低硅Nb-Ti钢的伸长率和强塑积分别达到了41%、25 256 MPa.%的最大值。  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

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通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。  相似文献   

14.
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.  相似文献   

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16.
Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

17.
The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.  相似文献   

18.
Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.  相似文献   

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