Sn含量对Zr-Sn-Nb-Fe-Cr合金相变温度和沉淀析出相的影响

以Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr与Zr-0.8Sn-0.3Nb-0.3Fe-0.1Cr2种不同Sn含量锆合金为研究对象,采用差示扫描量热法(DSC)测量2种锆合金的相变温度,探讨Sn含量变化对锆合金相变点的影响。同时,采用SEM对热轧态、热轧退火态、冷轧态、冷轧退火态、终轧态、终轧退火态6种加工工序样品分别进行详细的微观组织观察,随后通过定量金相法对2种锆合金在不同加工工序下的第二相大小及分布等特点进行对比分析,得出2种锆合金定量的统计结果。降低Sn含量对α→β相变点有明显影响,而沉淀析出相的颗粒形状基本不变,但是第二相颗粒平均尺寸减小。扫描电镜的能谱(EDS)分析半定量地说明Sn在锆合金中存在不同程度的成分偏析。     

终轧温度对443铁素体不锈钢组织、织构及成形性能的影响

通过光学显微镜、EBSD等分析技术,研究了终轧温度对443超纯铁素体不锈钢显微组织、织构、成形性能及抗表面起皱性能的影响规律。结果表明,降低终轧温度有利于促进443钢热轧退火态及冷轧退火态的再结晶,并使冷轧退火态组织更为细小均匀;降低终轧温度可有效强化冷轧退火态的γ纤维织构,是提高r值和杯突值、改善冷轧退火板成形性能、抗表面起皱性能的有效方式。     

终轧温度对铁素体不锈钢00Cr21Mo1织构的影响

通过金相和EBSD等技术,观察了不同热轧终轧温度对00Cr21 Mo1铁素体不锈钢热轧态、热轧退火态和冷轧退火态织构变化的影响情况,并分析讨论了较高终轧温度下铁素体不锈钢00Cr21 Mo1塑性应变比(Rm)较低的原因。结果表明,较低的终轧温度下,00Cr21 Mo1热轧态组织形变带宽度较小,受轧辊切应变而形成的{110}001、{110}112、{4 4 11}11 11 8织构组分强度较小,且均匀、分散,最终冷轧退火态以{111}面织构为主,塑性应变比较高。     

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 本文通过金相和EBSD等技术,观察了不同热轧终轧温度对00Cr21Mo1铁素体不锈钢热轧态、热轧退火态、冷轧退火态织构的变化的影响情况,并分析讨论了较高终轧温度下铁素体不锈钢00Cr21Mo1塑性应变比（Rm）较低的原因。结果表明,较低的终轧温度下,00Cr21Mo1热轧态组织形变带宽度较小,受轧辊切应变而形成的{110}<001>、{110}<112>、{4 4 11}<11 11 8>织构组分强度较小,且均匀、分散,最终冷轧退火态以{111}面织构为主,塑性应变比较高。     

热轧工艺对21%Cr铁素体不锈钢组织性能的影响

在实验室研究了21%wtCr铁素体不锈钢的热终轧温度、卷曲温度、热轧退火温度对铁素体不锈钢退火组织、力学性能和成形性能的影响。结果显示,随着终轧温度、卷曲温度的升高,材料的再结晶温度升高,而热轧后不同的退火温度必然得到退火板的完全再结晶组织和织构。通过热轧后退火温度的优化可以使最终冷轧退火产品具有相同的组织、织构和成形性能,能消除终轧温度对铁素体不锈钢成形性的影响。     

终轧温度对含钛铌超低碳铁素体不锈钢显微组织、织构和力学性能的影响

实验室研究了终轧温度对钛、铌复合添加的16%Cr超低碳氮铁素体不锈钢的显微组织、织构和力学性能的影响。结果表明,当终轧温度从940℃降低到800℃时,热轧退火钢板和冷轧退火钢板的铁素体晶粒尺寸均减小,因此采用低温终轧有利于细化铁素体晶粒。降低终轧温度,热轧退火后钢板中形成的γ纤维明显增强且比较均匀。由于织构具有遗传性,在冷轧退火钢板中也形成了均匀的γ再结晶织构。采用较低的终轧温度既有利于提高成型性又有利于改善材料的各向异性。     

冷轧低碳钢终轧温度试验对比分析

对冷轧低碳钢DC01热轧生产时设定不同的终轧温度,通过金相和拉伸实验,对比其热轧基板内部显微组织及力学性能的差异,并对比了冷轧和退火后其冷轧成品内部组织和力学性能的差异。试验结果表明,在终轧温度低于奥氏体向铁素体转变的开始温度Ar3时,热轧基板表层会随着终轧温度的降低出现越来越严重的混晶缺陷,通过冷轧及退火再结晶,表层混晶缺陷能够得到一定改善。轻微混晶缺陷不会直接对带钢热轧及冷轧力学性能数据产生明显影响,但会增大塑性应变比r值的各向异值|Δr|,即增加了材料的各向异性。     

含磷高强IF钢的析出物与深冲性能

通过实验室冶炼含磷高强IF钢,并经锻造、热轧、卷取、冷轧和连续退火,利用扫描电镜和XRD等设备观察其内部的二相粒子和织构特征,研究了轧制工艺参数和退火工艺对含磷高强IF钢最终深冲性能的影响。结果表明,奥氏体区终轧条件下,降低终轧温度和和提高卷曲温度能够提高r值。在本次试验条件下,终轧温度930℃、卷取温度740℃,试验钢能够获得较好的成形性能,经冷轧并连续退火后,能够达到含磷高强IF钢的目标要求。     

喷射沉积2195铝锂合金轧制板材晶粒组织及性能控制研究

研究了喷射沉积制备2195铝锂合金锭坯挤压板坯经不同终轧温度热轧至6mm厚度板材,以及经不同中间退火后再冷轧至6mm厚度板材固溶后的晶粒组织。结果表明,终轧温度290℃时,热轧板固溶后表层为粗大再结晶晶粒,而中心层为细长纤维状晶粒;终轧温度降低至220℃时,虽然表层再结晶晶粒尺寸减小,但中心层转变为尺寸粗大的长条状再结晶晶粒。板材中尺寸1μm以上的富Cu第二相粒子数量随中间退火(空冷)温度的增加(从330℃提高至450℃)而增加;冷轧固溶后表层等轴状再结晶晶粒尺寸增加,而中心层晶粒逐渐由粗大长条状再结晶晶粒转变为细小等轴状再结晶晶粒。适当温度中间退火、随炉冷却并冷轧、固溶后表层和中心层全部为细小等轴状再结晶晶粒。优化中间退火后的冷轧板材T8时效态强度最高,而终轧温度220℃的热轧板材T8时效态强度最低。     

Ti-IF钢中第二相粒子对性能的影响

研究第二相粒子在热轧过程中析出及冷轧退火过程中析出物的变化对性能的影响。结果表明,采用低温加热、终轧及高温卷取的热轧工艺可获得有利于性能的微观组织和析出物形态。随着退火温度升高,第二相粒子的聚集长大有利于延伸率和r值的升高。退火温度由820℃升高到860℃,Ti-IF钢在170 m/min和220 m/min两种退火速度下的强度有所下降,延伸率和r值上升。退火速度主要影响强度、延伸率和r值,随着退火速度的升高,强度、延伸率和r值升高。     

Zr-Nb、Zr-Sn-Nb合金轧制板材织构分析

采用电子背散射衍射(EBSD)技术对Zr-Nb、Zr-Sn-Nb两类锆合金的终轧退火板材组织、织构进行了研究,并对再结晶晶粒的取向差进行了表征。结果表明,两类锆合金经终轧退火后都得到了均匀细小的再结晶组织,多数晶粒尺寸在2～5μm之间;两种合金中形成的第二相差别很大,Zr-Sn-Nb合金中第二相均匀弥散,而Zr-Nb合金中第二相则存在两种形态;两种合金退火后织构均为基面平行于轧面的取向织构,并向TD方向偏转一定角度,且多数晶粒的1210∥RD方向。     

热轧工艺对超纯Cr17铁素体不锈钢成形性能的影响

对一种铌、钛双稳定化的超纯Cr17铁素体不锈钢分别进行常规热轧和低温热轧,再依次进行相同的退火、冷轧及最终再结晶退火处理。对比研究两种热轧工艺对组织、织构演变及成形性能的影响规律。结果表明,与常规热轧相比,低温热轧能显著细化热轧组织、弱化α纤维织构并强化γ纤维织构,最终使冷轧退火板的γ纤维再结晶织构明显增强、偏离{111}<121>组分的程度显著降低,使珋r值增大、△r值减小。低温热轧是改善超纯Cr17铁素体不锈钢成形性能的有效途径。     

Influence of the manufacturing processes on the corrosion of Zr-1.1Nb-0.05Cu alloy

To obtain a good corrosion resistance for a Zr-1.1Nb-0.05Cu alloy, various manufacturing processes were applied, and corrosion and a microstructural analysis were performed. This alloy was manufactured by applying four types of manufacturing processes controlled by a combination of the annealing temperature and reduction schedule. The corrosion resistance was increased with a decreasing intermediate annealing temperature, and a decreasing the final annealing temperature. Since the size and distribution of precipitates was decreased by applying the low temperature annealing, the corrosion rate of the Zr-1.1Nb-0.05Cu alloy could be controlled by a coordination of the intermediate and final annealing conditions.     

轧制工艺对N36锆合金带材微观结构的影响

利用扫描电镜(SEM)、透射电镜(TEM)和电子背散射衍射(EBSD)等方法,对不同轧制工艺制备的N36锆合金带材中的第二相、晶粒尺寸和微观织构进行了研究。结果表明,锆合金带材中织构主要以{0001}$\bar{1}2\bar{1}0$和{0001}$01\bar{1}0$两类基面织构为主,第二相粒子主要为HCP型Zr(Nb, Fe)₂粒子。在热轧总变形量一致的情况下,热轧工艺道次变形量的变化对最终带材的晶粒尺寸和微观织构影响不大,但是对第二相粒子的尺寸有很大影响。热轧过程第一道次变形量越大,最终带材中第二相粒子尺寸越小。在热轧过程中,换向轧制会影响最终带材的织构组成,也会促进锆晶粒的[0001]轴平行于带材的ND方向;同时在带材的轧面(RD-TD 面)上,晶粒的取向性减弱,晶粒取向更加随机。终轧过程中的变形量增大,会使最终带材的晶粒尺寸减小,再结晶程度提高,使得最终带材中{0001}$\bar{1}2\bar{1}0$织构增强,而{0001}$01\bar{1}0$织构减弱。     

Influence of Finish Rolling Temperature on Microstructure and Mechanical Properties of a 19Cr1.5Mo0.5W Ferritic Stainless Steel

A 444-type heat-resistant ferritic stainless steel containing 0.05 wt% Ce(rare earth element) and 2 wt%(Mo+W) was adopted as an experimental material to study the effect of finish rolling temperature on microstructure and texture evolution as well as on mechanical properties and formability.The rolling processes contain hot rolling at two different finish rolling temperatures(860℃ and 770℃) and annealing,cold rolling and subsequent annealing.It was found that the microstructures after hot rolling and annealing could be refined by lowering finish rolling temperature.The resultant microstructures after cold rolling and annealing were hereditarily refined.Lowering finish rolling temperature can weaken α-fiber texture in hotrolled or cold-rolled ferritic stainless steel strip,while γ-fiber texture in the final product was homogeneously strengthened.Additionally,enhanced mechanical property and formability in terms of strength and average plastic strain ratio could be obtained via decreasing finish rolling temperature.     

Zr-Sn-Nb-Fe锆合金板材轧制及热处理过程中的晶粒组织演变

采用光学显微镜(OM)和扫描电镜(SEM)分析研究了Zr-Sn-Nb-Fe锆合金板材在热轧及退火→中间冷轧及退火→成品轧制及退火的全工艺流程中晶粒组织的演变规律。结果表明,热轧后合金组织沿轧制方向呈带状分布,晶粒粗大并破碎变形;中间冷轧和成品轧制后合金为沿轧制方向带状分布的细小形变组织,合金组织明显细化;中间退火和成品退火后合金中晶粒再结晶程度较热轧退火时明显提高,晶粒取向差逐渐向正态分布变化,晶粒组织也逐渐均匀化和细化,最终获得细小、均匀分布的完全再结晶晶粒组织,晶粒度12级。     

Effect of heat treatment on the Nb distribution and corrosion resistance of Zr-Sn-Nb-Fe zirconium alloy

After being treated in different ways,Zr-Sn-Nb-Fe alloy specimens are exposed in 0.01mol/L LiOH aqueous solution at 350℃ under 16.8 MPa.The examination of microstructures and second phase particles (SPPs) of these specimens was carded out by high-resolution transmission electron microscopy (HR-TEM).The specimens treated at 800℃ before the final cold roiling have a better corrosion resistance than those treated at 680℃,and the specimens treated at 500℃,after the final cold rolling,have a better corrosion resistance than those treated at 560℃.TEM examination shows that the SPPs existing in the 800℃/500℃ specimen,which has the best corrosion resistance,contains a lot of Nb dement,which results in the reduction of the niobium content in the a-Zr solid solution.     

中间退火前后冷轧变形量对3003铝合金阴极箔比电容的影响

采用扫描电镜及能谱仪,透射电镜和比电容检测等方法研究了中间退火前后冷轧变形量对3003铝合金阴极箔第二相分布及比电容的影响.结果表明:随着最终冷变形程度的增加,位错密度增大,从而比电容值显著提高;最终冷轧变形量为90%时,比电容达到最大值,继续增加冷轧变形量,比电容值反而下降;但对于最终冷轧变形量95%的箔材,由于中间退火前冷轧变形量较低,使得退火过程中析出的弥散第二相数目减少,最终导致成品箔中的腐蚀位置减少,比电容降低.     

Corrosion behavior and microstructural characteristics, of the Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy with different manufacturing processes

The best manufacturing process for a high Nb-containing Zr-based alloy was determined by means of a corrosion test under a 400 °C steam condition, and a microstructural analysis was performed on the Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy, which was made with different manufacturing processes. This alloy was manufactured as sheets through the application of various manufacturing processes; the processes were controlled by a combination of the intermediate annealing temperatures and cold working steps after a water quenching of the β region. The corrosion behaviors of the Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy were clearly affected by the manufacturing conditions, and the corrosion resistance was considerably increased by the application of sequences of cold rolling and annealing. Microstructural analysis of the alloy sheets confirms that the corrosion resistance of the Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy can be estimated by a concentration of Nb in the precipitates, regardless of the manufacturing processes. Moreover, the pole figure evaluation of the oxide layers that formed on the Zr-1.5Nb-0.4Sn-0.2Fe-0.1Cr alloy sheets with different manufacturing processes verifies that the (111) and (200) textures of the monoclinic ZrO₂ phase are well developed when the corrosion resistance is increased.     

退火对新型锆合金组织与性能的影响

采用扫描电镜(SEM)、电子背散射衍射(EBSD)、X射线衍射(XRD)、透射电镜(TEM)和万能试验机等,研究真空退火对新型Zr-Nb-O-Cu锆合金微观组织与力学性能的影响。结果表明:在580℃、3 h退火条件下,合金的平均晶粒尺寸为2.5μm,晶粒为等轴晶,退火前后均存在{0001}á1010?和{0001}á1120?两种织构,但基面织构强度有所降低。第二相颗粒在晶内和晶界呈弥散分布,为体心立方(BCC)结构的β-Nb相与密排六方(HCP)结构的Zr-Nb-Fe相,尺寸集中在30~150 nm之间。相对于原材,退火后合金沿轧制方向(RD)和垂直方向(TD)的屈服强度(σs)及抗拉强度(σb)均下降,试样均韧性断裂。3个方向的应变硬化指数(n)与塑性应变比(r)差异明显。晶粒与第二相的尺寸、织构等因素对力学性能有重要影响。