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为了提高H08A焊丝钢的拉拔性能和焊接性能,对该钢种全流程进行取样分析,利用扫描电镜观察夹杂物的形貌,统计数密度,利用夹杂物自动分析系统对夹杂物成分变化和成分分布进行分析,利用FactSage热力学软件分析夹杂物低熔点区域分布。结果表明,钢中全氧含量可间接反映出夹杂物数密度水平,若没有LF精炼和中间包保护浇铸,铸坯中全氧很难达到要求的0.005%。夹杂物类型主要是硅锰铝氧化物的复合夹杂物,脱氧合金化后,夹杂物成分趋于稳定,大尺寸夹杂物多为MnO-SiO2-Al2O3,尺寸最大达到70 μm。钙收得率不高,在夹杂物中没有发现典型钙氧化物夹杂物。夹杂物主要是球形,大尺寸夹杂物总量较多,中间包和铸坯中80 μm以下大尺寸夹杂物占比较小,80 μm以上大尺寸夹杂物占比为87.6%~87.9%。 相似文献
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利用夹杂物自动分析系统在实验室中研究了钢中Ce含量对热影响区夹杂物演化的作用。结果表明,随着钢中Ce含量的增加,夹杂物的数量密度、平均尺寸和以Al_2O_3为核心的复合夹杂物比例都减少,夹杂物中Ce的含量和含Ce夹杂物的比例都增加,典型夹杂物核心由Al_2O_3+Ce_2O_3变为Ti_2O_3+Ce_2O_3,外部都析出MnS。当钢中Ce质量分数大于140×10~(-6)时,出现以Ti-Ce复合氧化物为核心的夹杂物。随着夹杂物中Ce含量的增加,钢中夹杂物的尺寸减小。Ce氧化物冶金工艺对夹杂物的细化作用明显。 相似文献
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采用MoSi2电阻炉在1〖KG-*9〗873 K下开展了含钙钡合金脱氧和非金属夹杂物控制技术研究。结果表明,各组实验终点钢中夹杂物平均长度均小于8 μm,并都有纯三氧化二铝夹杂物存在。采用含钙钡合金的复合脱氧工艺,终点钢中未发现含钡夹杂物,有较多以CaO Al2O3为主要成分的复合夹杂物,w(T.O)>50×10-6。用AlMnCa脱氧,终点钢样w(T.O)=37×10-6,含氧化钙夹杂物较少,大于20 μm的夹杂物数量占总夹杂物数量的1.2%。 相似文献
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1前言
钢中所含的以氧化物为主的非金属夹杂物使钢材在成形时产生裂纹或成为疲劳破坏的起因,而导致成形性和疲劳寿命恶化,或者成为轧制时线状缺陷产生的原因,极大地影响了产品质量。夹杂物的大小通常从〈10^-6m到数百10^-6m,钢的各种性能多数被夹杂物中大于某一尺寸的夹杂物所左右。假如清楚了夹杂物的起源,就可用改善工艺来控制夹杂物,在这方面有关夹杂物成分、大小及形态等资料并不少。因此,在对钢中夹杂物评价时,不仅就其数量,还必须正确测定其化学成分、大小及粒径分布。 相似文献
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结合工业化生产的无取向硅钢,进行了RH精炼喂CaSi线去除钢中的非金属夹杂物试验研究.针对不同的钙处理条件,分析了CaS夹杂生成热力学,观察了夹杂物的形貌和尺寸分布,确定了夹杂物的类型、数量,探讨了钙处理后钢中夹杂物的变化规律.结果表明,本试验条件下,钙处理可以有效抑制MnS、AlN夹杂物的生成,有效促进钢中微细夹杂物的聚合、上浮、去除,钢质纯净度明显提高.经过合适的钙处理后,钢中的夹杂物以独立存在的CaO为主,同时有少量含CaO、SiO2 、MgO的复合夹杂,没有发现CaS夹杂存在.这部分夹杂物的尺寸集中分布在2~20μm,数量约为1.8×105 个/mm3. 相似文献
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建立了基于扫描电子显微镜和能谱分析相结合的夹杂物原位统计分布分析方法,并对大尺寸D2动车组车轮纵剖面中轮毂、近轮毂辐板、近轮辋辐板、轮辋4个区域内的夹杂物的组成、类型、数量和尺寸进行了原位统计分布解析,探讨了不同区域内的各类夹杂物数量、尺寸和颗粒面积的分布规律,发现车轮中主要典型夹杂物为氧化物、条形硫化物、球形硫化物、氧硫复合物。其中氧化物、球形硫化物、氧硫复合物夹杂在轮辋区域数量最多,条形硫化物夹杂在近轮毂辐板最多;轮毂和轮辋区域的氧化物、球形硫化物、氧硫复合物夹杂物总面积普遍大于辐板区域,但轮辋区域的条形硫化物夹杂总面积小于其他区域;同时氧化物、球形硫化物、氧硫复合物这3类夹杂物颗粒尺寸主要集中于2~5 μm之间,条形硫化物尺寸大于10 μm占比最大,轮辋区域大尺寸夹杂颗粒数量占比最小,这与车轮制备工艺要求一致性较好。 相似文献
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为了获得高品质齿轮钢中更加确切的夹杂物信息,并评价齿轮钢中的夹杂物,选择高品质Mn-Cr系齿轮钢为研究对象,分别利用评级法、电镜检验法、极值法等对钢中夹杂物进行了研究。结果发现,评级法、电镜检验法获得的氧化物夹杂尺寸分别在16、23 μm以下,尺寸相对较小。而通过扫描电镜大面积检测分析,试验钢中最大氧化物夹杂等效尺寸达到34.2 μm。进一步利用Gumbel统计极值法对试验钢中最大夹杂物预测,在99.9%概率条件下,试验钢中最大夹杂物尺寸为62.1 μm。99.9%的概率条件相当于约100 000 mm2检测面积,对于工业及常规科研检测分析已足够充分。 相似文献
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采用电解法和扫描电镜研究了300 t转炉-RH精炼钙处理对无取向硅钢板(%: ≤0.005C、1.2~2.2Si、0.2~0.6Mn、≤0.20P、≤0.005S、0.2~0.6Al、0~0.01Ca)中夹杂物的影响。结果表明,钢中Al含量为0.25%和0.35%时,钢中溶解氧均小于1×10-4%,钙处理后都会产生CaS夹杂物,尤其是含0.35%Al的钢水;钙处理可以有效减少钢中的夹杂物数量,尤其是0.5μm以下的微细夹杂物数量;钙处理后夹杂物的种类以AlN、CaS为主,同时还含有少量的氧化物夹杂物以及AlN-CaS复合夹杂物,尺寸主要为1.5~5.0μm。 相似文献
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Stephano P.T. Piva Deepoo Kumar P. Chris Pistorius 《Metallurgical and Materials Transactions B》2017,48(1):37-45
This work investigated the use of FactSage macros to simulate steel–slag and steel–inclusion reaction kinetics in silicon-manganese killed steels, and predict oxide inclusion composition changes during ladle treatment. These changes were assessed experimentally using an induction furnace to simulate deoxidation and slag addition. The average steel mass transfer coefficient for the experimental setup was calculated from the analyzed aluminum pick-up by steel. Average oxide inclusion composition was measured using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Confocal laser scanning microscopy was used to assess the physical state (solid or liquid) of oxide inclusions in selected samples. The changes in the chemical compositions of the oxide inclusions and the steel agreed with the FactSage macro simulations. 相似文献
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The paper deals with investigations concerning the structure and state of dispersive precipitations of the phases consolidating in the high-strength steel Weldox 1300 after its high temperature thermomechanical treatment.Making use of transmission technique of electron microscopy (TEM) mainly the microstructure and morphology of martensite was analysed,as well as the state of dispersive precipitations of carbides and nitrides resulting from microadditives of such alloys as Nb,V,Ti or B,introduced into the steel.Observations revealed both a fine lathed and twin structure of the matrix of martensite in the investigated steel.By means of the method of electron diffraction particles of secondary strengthening phases of the M(C,N) type of a nanocrystalline size could be identified,and also non-metallic oxide inclusions,affecting the mechanism of strengthening of the investigated steel. 相似文献
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���£�֣��ѧ�ã����ǿ������ 《钢铁研究学报》2017,29(12):973-981
The characteristics of inclusions in high strength structural steel were characterized by scanning electron microscopy and energy dispersive spectroscopy. The influence of Ti- alloying and Ca treatment on the composition of inclusions in the steel was investigated, and the effect of oxides on the precipitation behavior of TiN and its refining effect on the microstructure were studied. The results show that the inclusions in the steels are Al- Ti- Mg- O system with spherical or polygonal shape after adding Ti, which furtherly can be effectively modified into spherical inclusions after adding Ca. The TiOx in inclusions can be reduced by Ca treatment and Ti gradually diffuses into the surface of the inclusions, which promotes the local precipitation of TiN on the surface of the composite oxides. The amounts of fine oxides and nitrides in steel increase with the increase of Ti mass percentage. Therefore, Ca treatment and higher Ti content can promote the formation of the inclusions of composite oxide and TiN, and also delay the homogeneous nucleation time of TiN inclusions, reducing its size during solidification process of the steel. TiN with the size about 2-3??m not only can induce polygonal ferrite, but also induce acicular ferrite. Specially, the inclusions with TiN and MnS locally precipitating on the surface of composite oxides are conducive to the nucleation of interlocking acicular ferrites. 相似文献
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The weathering steels are prone to pitting corrosion in an environment containing chloride ions.The pitting behavior of Cu-P-RE weathering steels and its effect on the corrosion resistance of steels were investigated by multifarious analytical techniques,such as field emission-scanning electron microscopy(FE-SEM),electron probe microanalysis(EPMA),scanning Kelvin probe force microscopy(SKPFM),electrochemical workstation and a series of immersion tests.The results show that the original stripshap... 相似文献
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摘要:20MnCr5齿轮钢通常有较好的疲劳性能及切削性能,而钢中夹杂物是影响这些性能的重要因素。为了研究镁对20MnCr5齿轮钢中夹杂物的改质行为和规律,开展了相应的工业实验,采用金相显微镜、扫描电镜以及非水溶液电解腐蚀技术对铸坯和轧材进行了分析。结果表明:镁处理后,钢液更加洁净,夹杂物数量变少,尺寸也变小;以Al2O3为核心外围包裹着MnS的复合夹杂,转变为以MgO·Al2O3为核心外围包裹着MnS的复合夹杂物,且复合夹杂物的占比从4.2%提高到8.3%。对轧材进行分析,发现镁的加入使20MnCr5轧材中长条状的硫化物更加短小弥散,硫化物的细系评级从2.5级显著降低到1.5级;由于复合夹杂物内部硬质MgO·Al2O3核心抑制了轧制过程中夹杂物的变形,使夹杂物保持球形或椭球形。 相似文献
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