不同冶炼工艺制造的核级690合金传热管冶金质量及组织性能对比分析

对采用真空感应+电渣重熔及电弧炉+炉外精炼+电渣重熔两种不同冶炼工艺制造的核级690合金传热管化学成分、非金属夹杂物等冶金质量及组织力学性能、腐蚀性能进行对比分析,同时与国外进口同类产品进行对比。结果显示,采用真空感应+电渣重熔冶炼工艺生产的核级690合金传热管在某些元素和非金属夹杂物控制等冶金质量,以及点腐蚀性能方面优于电弧炉+炉外精炼+电渣重熔冶炼的,晶间腐蚀性能略优于电弧炉+炉外精炼+电渣重熔冶炼的,组织力学性能、均匀腐蚀性能、应力腐蚀性能等与电弧炉+炉外精炼+电渣重熔冶炼的差异不大,性能相当。     

国外合金工具钢的冶金生产工艺

1.冶炼工艺近年来国外一般采用三种冶炼工艺生产合金工具钢,即: (1) 电弧炉熔炼;(2)电弧护熔炼 护外二次精炼, (3)电弧炉熔炼、制造电极十电渣重熔或真空自耗电极重熔。随着炉外精炼设备和技术的普及,炉外精炼逐渐     

UNS NO6600合金（GH600）生产试制

UNS NO6600合金采用二种冶炼工艺进行了生产试制，出于对降低成本和大批量生产考虑，我公司主要采用非真空感应炉＋电渣重熔工艺生产UNS NO6600合金。非真空感应炉＋电渣重熔与真空感应炉＋电渣重熔一样，各项技术指标均满足技术条件要求。     

《特殊钢》1986年总目录

,冶炼·电弧炉加钢包喷Ca一si粉生产socrvA阀片钢电渣重熔小型冷轧辊多元回归分析法在Cr:3型不锈钢中的应用小岭石灰基粉剂用于铁水予处理的效果在非真空感应炉中使用真空铬冶炼超低碳不锈钢00Cr18Ni14MoZCuZ的研究适用于电渣重熔工艺的合成渣的物理一一力学性能高铬不锈钢喷粉     

镍基高温合金的熔炼工艺研究进展

镍基高温合金的熔炼方法是合金质量的决定性因素，真空感应熔炼可有效控制合金锭中O、N、H等气体及有害杂质元素含量，精确控制合金成分。在此基础上，对合金进行重熔（电渣重熔及真空自耗重熔），可进一步降低合金中S、P等有害杂质含量，消除成分偏析及缩孔等缺陷，对凝固组织进行优化调控，从而实现大规格高质量合金锭的熔炼。本文综述了镍基高温合金的熔炼工艺进展，重点介绍了真空感应熔炼、电渣重熔、真空自耗重熔等常用熔炼技术的原理和特点，论述了“真空感应熔炼+保护气氛电渣重熔”、“真空感应熔炼+真空自耗重熔”双联工艺，以及“真空感应熔炼+保护气氛电渣重熔+真空自耗重熔”三联工艺在镍基高温合金熔炼方面的研究进展，并对镍基高温合金熔炼工艺的选择和发展方向提出建议。     

真空电渣重熔炉发展前景的探讨

真空电渣重熔炉是在真空电弧重熔炉和气体保护电渣炉的基础上发展起来的一种冶炼高性能合金的特殊真空重熔冶金装备。真空电渣重熔炉冶炼的钢种和合金有优质合金钢,高温合金,精密合金,耐蚀合金,铝、钛、银等合金。介绍了真空电渣重熔炉的工作原理,冶金特点,比较了真空电弧重熔、普通电渣重熔和真空电渣重熔的钢材的冶炼成本、冶金质量和性能,并讨论了真空电渣重熔炉的应用前景。     

Fe-Cr-Al高电阻电热合金的冶炼工艺探讨

OCr25Al5高电阻电热合金具有良好的耐氧化性和高的比电阻,它与常用镍铬合金比较,具有以下优点:①使用温度较高,长期使用温度达1200℃以上,短时温度可以达1300℃。②不含贵重元素镍,节省大量的资源,成本较低。③在氧化气氛中,一般情况下,在同一使用温度较镍铬合金具有较长的寿命。④铁铬铝合金具有较高的电阻率,较小的比重,在使用温度每平方厘米能承受较大的瓦特负荷。因此在同样功率时,用量较小。一般铁铬铝合金的冶炼工艺采用中频十电渣、真空感应炉冶炼,高频冶炼以及电弧炉冶炼等多种工艺。其中以中频十电渣的冶炼工艺较为普遍,本厂亦采用中频十电渣的双联冶炼工艺。     

真空感应炉炉衬材质对Inconel 690合金纯净度的影响

 为了研究坩埚材质对真空感应炉熔炼镍基合金Inconel 690纯净度的影响,在200、500kg真空感应炉上,分别使用镁质坩埚、钙质坩埚、铝镁质坩埚冶炼了Inconel 690合金,分析了产品中全氧含量、硫含量及氧化物夹杂数量、尺寸。真空感应炉铝镁质坩埚冶炼的产品全氧含量可达到(10~15)×10-6(质量分数,下同),硫含量55×10-6,合金中存在粒径5~10μm的D类夹杂物和粒径50μm以下的B类夹杂物,产品纯净度较高。钙质坩埚冶炼的产品硫含量可达到10×10-6,全氧含量平均为33×10-6,合金中存在大量的粒径5~10μm的D类细小夹杂物,同时存在少量粒径50~100μm的大型钙硅酸盐夹杂物。镁质坩埚冶炼的合金中全氧、硫含量分别为28×10-6、55×10-6,存在大量粒径50μm以上的B类氧化物夹杂。Inconel 690合金通常采用真空感应炉加电渣重熔的工艺路线生产,不考虑硫含量对纯净度的影响,建议真空感应炉采用铝镁质炉衬冶炼Inconel 690合金。     

镍基耐蚀合金N10276开坯开裂原因分析和工艺改进

采用3t VIM真空冶炼+3 t电渣重熔双联工艺生产的镍基耐蚀合金N10276在开坯过程中极易出现开裂缺陷.采用微观组织表征、能谱检测以及透射电镜标定等方式对缺陷进行了分析,并用热力学计算与差式扫描量热法确定析出相重新固溶条件,并通过热压缩模拟对改进措施进行了验证.结果表明,合金中析出的μ相是造成锻造开坯过程中开裂的直...     

冶炼方法和热处理工艺对0Cr12Mn5Ni4Mo3Al 高强不锈钢带力学性能和组织的影响

 研究了热处理对采用电炉+炉外精炼（LF）+电渣重熔冶炼的工业用和实验室50 kg真空感应炉+电渣重熔冶炼的试验用0Cr12Mn5Ni4Mo3Al高强度不锈钢带（0.8 mm和0.5 mm）的力学性能和组织的影响。结果表明,实验室得到的钢材更为洁净,组织中保留有合理的残余奥氏体含量;与采用同样热处理制度的工业钢带相比,在保持或提高伸长率的同时,抗拉强度提高50~85 MPa,杯突值提高1~3 mm;适当调节Cr、Ni的当量比以及采用合理的锻造、轧制工艺可以消除钢带组织中δ 铁素体的不利影响,更大限度发挥材料潜力。     

转炉炉壳热应力分析

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。     

焦炭热性能指标意义浅析

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。     

Results of treatment of cancer of the cardia

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.     

Effect of antibiotics of chemotaxis of human leukocytes

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.     

Quality of life of relatives of mental patients

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.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

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)