304不锈钢中的夹杂物及其冷轧变形行为

非金属夹杂物是引起冷轧板坯表面缺陷的主要原因.分析了304不锈钢热轧板坯中非金属夹杂物的成分、形貌及尺寸.对304热轧板坯进行不同压下量的轧制,分析不同厚度冷轧板坯中的夹杂物形状和尺寸,研究非金属夹杂物在板坯冷轧过程中的变形行为.结果表明:304热轧板坯中的夹杂物主要组成为CaO-SiO2-MgO-Al2O3的复合氧化物,为脆性夹杂物;冷轧过程中,夹杂物的塑性变形不明显,随着冷轧压下量的增加,大颗粒的夹杂物不断被轧碎,板坯中夹杂物的平均尺寸逐渐减小.     

轴承钢铸态非金属夹杂物的组成

对我厂轴承钢铸态非金属夹杂物的鉴定分析是用金相法与电子探针法相结合完成的。10~(?)电弧炉氧化法冶炼的GCr15及GCr15SiMn610Kg锭型中,其脆性夹杂物和点状夹杂的化学成分组成相同,均是镁尖晶石为核心的铝酸钙,外包有硫化物包裹层的三层复合夹杂物。塑性夹杂物为硫化锰,也往往以镁尖晶石为结晶核心。     

钙处理齿轮钢中氧硫复合夹杂物的热变形能力

采用金相分析、扫描电镜和能谱仪等分析手段,研究了钙处理加硫的DIN18CrNiMo7-6齿轮钢中氧硫复合夹杂物的形貌、成分和热变形行为.结果表明:外围硫化物的钙抑制了氧硫复合夹杂物的变形,当外围硫化物的钙原子分数约为5.0%时抑制作用达到饱和;高熔点核心氧化物的面积分数增加,复合夹杂物的变形能力降低,而低熔点核心氧化物对复合夹杂物变形能力的影响不明显.     

钛微合金化钢中硫化夹杂物的态别定量

为探讨加钛引起的微合金化钢硫化物的变态作用,研究了钢中硫化物的态别定量。我们改进了冶金部分析情报网推荐法,提高了ＭＳ相的分析精度。对含有Ｆｅ＿３Ｃ,Ｔｉ＿４Ｃ＿２Ｃ＿２,ＭＳ,ＴｉＣ,ＴｉＮ,ＴｉＣＮ的多相体系提出了一个硫化夹杂物的态别定量法并研究了有关的氮化物、硫化物和碳化物的析出现律。     

硫化锰对钢中Sb析出行为的影响

研究了钢中不同夹杂物对Sb的析出和高温氧化过程中富集行为的影响.Fe-1.5%Sb合金1100℃水冷试样中Sb在钢中主要析出位置是晶界.与单一的氧化物夹杂相比,硫化锰是更为有效的Sb异质形核核心,且Sb析出相成分组成接近于FeSb相.实验结果与二维错配度理论计算结果相一致.通过降低氧含量,钢中加入Ti变质硫化锰夹杂等方式,增加了MnS数量,使得更多的Sb在夹杂物上析出,从而减少钢中Sb的偏析和固溶量,改变Sb在钢中的析出位置.     

硫含量对重轨钢中非金属夹杂物的影响

摘要：实际生产过程中由于原料和操作控制不精确,钢中硫含量和非金属夹杂物波动较大,严重影响钢的洁净度。为了准确控制重轨钢中硫化锰等非金属夹杂物的尺寸、形态和数量,在实验室开展了硫含量对重轨钢中非金属夹杂物的影响研究。钢中硫质量分数增至70×10-6、110×10-6、140×10-6后随炉冷却,采用全自动夹杂物分析仪对钢中非金属夹杂物进行统计,获得了硫含量与钢中非金属夹杂物成分、尺寸、形态和数量的关系。结果表明,钢中夹杂物大部分为以氧化物为形核核心的复合型MnS;随着硫含量的升高,复合型MnS、MnO-SiO2和MgO-Al2O3-SiO2-CaO型夹杂增多,CaO-SiO2和MgO-CaO-SiO2夹杂减少;夹杂物平均尺寸随硫含量的升高而增大,且不同尺寸的夹杂物均有所增加,尺寸为2~10μm增多最明显;硫质量分数为(70~140)×10-6的钢液凝固过程液相中都能单独析出MnS,且硫含量越高,MnS析出越早,含量越多。     

钢中的非金属夹杂物

提出一种用于稳定供电电压的静止无功补偿的有效控制方法。该方法在计算机内存中以表格形式建立ΔＱ＝ｆ（ΔＶ）曲线，根据电压偏移量查表控制静补装置的无功功率输出，并在无功调节过程中动态修改曲线，使之趋近真实情况。仿真结果和动模实验验证了其可一和有效性。     

热处理对铸态钢中硫化锰夹杂物的影响

基于1215易切削钢成分,采用Factsage软件对Mn-S-O-Fe体系进行热力学计算,并将铸坯样在不同温度进行热处理,运用金相显微镜、扫描电镜对热处理前后钢中硫化锰的变化进行了研究.结果 表明,硫化锰在800℃热处理时开始出现晶间析出现象,析出的硫化锰在热处理后发生聚集长大的球化现象,且温度越高,球化现象越明显.经...     

锰原料对低合金TRIP钢中非金属夹杂物的影响

为了研究不同锰合金原料对TRIP钢洁净度的影响及锰合金中非金属夹杂物的遗传特性,采用SEM-EDS分别检测了电解锰、金属锰和中碳锰铁中非金属夹杂物的类型、形貌和尺寸,并通过高温试验和热力学计算系统探讨了采用3种锰原料进行合金化后TRIP钢中非金属夹杂物特征.结果表明,电解锰中夹杂物主要为MnC、MnC-MnO和MnO-...     

集装箱钢连铸薄板坯中的夹杂物行为

对珠钢 CSP薄板坯连铸机生产的横断面为 1180 mm× 5 0 mm的集装箱钢薄板坯中的夹杂物进行了研究 ,得到了薄板坯中夹杂物的种类、数量、大小及分布规律。还讨论了夹杂物对产品性能的影响及减少铸坯中的夹杂物一些措施     

钛合金热变形行为研究

综述了国内外钛合金热变形行为的研究进展,分析了几种典型的α钛合金、近α钛合金、α+β钛合金及β钛合金的在不同的热变形条件下的流变应力的行为特征,软化机制,表观激活能及组织演变规律。介绍了氧、氢元素和不同的组织状态对钛合金热变形的影响。     

Deformation Behaviour and Microstructural Evolution During Hot Compression of AISI 904L

The hot deformation behaviour and microstructural evolution of AISI 904L super‐austenitic steel has been investigated by means of hot compression tests. The tests were carried out on a Gleeble 1500D thermo‐mechanical simulator in the temperature range from 850 °C to 1150 °C and at strain rates range from 0.001 s^?1 to 5 s^?1. The microstructure evolution was examined by means of light optical microscopy (LOM). The results show that after an initial deformation hardening, softening mechanisms occur. The peak stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zener–Hollomon parameter in the hyperbolic‐sine equation with the activation energy for deformation of 463 kJ/mol. The steady state was achieved at maximum strain of 0.9 only at the lower strain rates (under 1 s^?1) and the higher temperatures (above 1100 °C). Microstructural analyses showed a gradual increase in the dynamically recrystallized area with an increase of the temperature and a decrease of the strain rate. The grain size did change, as expected, correlating to the deformation conditions.     

Hot‐Rolling Experiments on Deformation Behaviour of Oxide Scale

A new test technique developed by the authors allows to investigate the brittle‐ductile behaviour of oxide scale during the hot‐rolling process. Sandwich specimens were pre‐oxidised and then welded so as to be gas‐tight. A micro‐alloyed deep‐drawing quality steel (interstitial free steel) and a fine‐grained low‐pearlite structural steel served as test material. The experiments were performed at temperatures up to 1050 °C. Optical metallography was used to describe the changes of the scale layers. The method is quite good to describe the results qualitatively whereas it is rather difficult to derive quantitative results.     

MnS夹杂对钢中氢扩散行为的影响

通过实验和有限元计算研究了MnS夹杂对钢中氢扩散行为的影响.结果表明:当MnS夹杂长度取向与氢渗透方向平行时,氢在钢中的表观扩散系数随MnS含量的增加而增加;当MnS夹杂长度取向与氢渗透方向垂直时,氢在钢中的表观扩散系数随MnS含量的增加而降低.对于具有扩散通道效应和陷阱效应的第二相,它对氢扩散的影响取决于扩散通道效应和陷阱效应的强弱以及第二相的形状、数量和取向.     

3104铝合金热变形流变应力模型

采用等温压缩试验，研究了3104铝合金在应变速率为0．001-1s^-1、变形温度为573-773K条件下的流变应力行为。结果表明，3104合金流变应力对应变速率和变形温度十分敏感，合金高温塑性变形时存在稳态流变特征，并建立了合金热变形流变应力模型。     

Hot Ductility of DSS and Its Microstructure Observation During Hot Deformation

By selecting several typical duplex stainless steels (DSS), i. e., 00Cr22Ni5Mo3N, 00Cr21Ni2Mn5N and 00Cr25Ni7Mo4N, as research materials, hot ductility characteristic of DSS was studied by thermal simulation method and microstructure evolution during hot compression was observed through TEM. The results show that the optimum hot ductility temperature range of DSS is 1050–1200°C. 00Cr25Ni7Mo4N exhibits the worst hot ductility and 00Cr21Ni2Mn5N has similar hot ductility to 00Cr22Ni5Mo3N. During hot compression, the dynamic recovery of austenite occurs in DSS while the dynamic recovery and reerystallization of ferrite take place in 00Cr22NioMo3N and 00Cr21Ni2Mn5N, but only the dynamic recovery of ferrite can be observed in 00Cr25Ni7Mo4N.     

Hot Deformation Behaviour of Low Alloy Steel

Hot deformation of a continuously cast low alloyed steel is studied by means of hot compression and tensile tests by using a Gleeble® 1500 machine after austenitization in a wide range of strain rates and between 720–800 °C. The flow data are evaluated to obtain the strain rate sensitivity and the processing maps. A new calculation method is used, yielding on the instability parameter defined as κ_J which correlates well with the microstructural changes. The strain rate sensitivity does not predict any instability but all the others instability parameters do, including the new κ_J. Flow instability appears at high temperatures and low strain rates where pores are formed at the austenitic grain boundaries, causing a decay of ductility in the tensile test. During hot deformation more ferrite is formed than corresponding heat treatments without deformation. In these conditions, the deformation is concentrated in the softer ferrite phase. The deformation induced ferrite deforms by dynamic recovery forming new grains as revealed by metallography and is correlated with low coefficients of power dissipation. The sinh type constitutive equation represents the flow data well with a stress exponent n = 4.1 and an apparent activation energy Q = 218 kJ/mol.     

重轨钢中MnS析出热力学和动力学分析

 采用无水有机溶液电解法分离提取重轨钢中的MnS夹杂物,采用扫描电镜观察铸坯内和钢轨中MnS夹杂物的三维形貌,并结合能谱仪分析其成分。铸坯被轧制成钢轨后,相应的MnS夹杂物都沿着轧制方向被轧制成长条状。基于热力学和动力学模型,分析重轨钢中MnS夹杂物析出行为以及在钢液凝固过程中锰元素和硫元素偏析的程度。热力学分析表明,MnS夹杂物在凝固末期凝固分数为0.94时开始析出,其析出量由初始[w([Mn])]和初始[w([S])]决定,且在凝固过程受到冷却速率的影响,对比发现,热力学的计算析出结果与Thermo-Calc和FactSage6.4的计算结果有较好的一致性;动力学分析表明,在钢液凝固过程增加冷却速率,凝固析出的MnS颗粒尺寸将减小。通过调整钢中[w([Mn])]和[w([S])]以及改变冷却速率,可以控制MnS的析出时机和形态,减小其对钢性能的有害影响。     

TiNiNb合金热变形流变行为的研究

采用Gleeble-1500热模拟试验机对TiNiNb合金进行了高温压缩变形实验, 分析了该合金在变形温度为800～1050 ℃, 应变速率为0.01～10 s~(-1)条件下的变形行为及流变应力的变化规律. 结果表明, 流变应力受变形温度和应变速率显著影响, 流变应力随变形温度的升高和应变速率的降低而降低. 采用双曲正弦模型确定了该合金的变形激活能Q和应力指数n, 建立了相应的热变形本构关系.