72钢制绳钢丝的力学性能试验

用光学显微镜、扫描电镜、拉伸、扭转及弯曲试验机研究了热处理态72钢的显微组织及不同道次72钢制绳钢丝的力学性能。结果表明,热处理态72钢室温组织为索氏体＋少量铁素体。钢丝经3.00 mm→1.30 mm九道次拉拔后强度值波动不大,强度、扭转及弯曲值均高于重要用途制绳钢丝标准值,可用于一般和重要用途的钢丝绳工业生产。     

Online nondestructive testing for fine steel wire rope in electromagnetic interference environment

The diameter of fine steel wire rope (FSWR) is generally a few millimeters. Its magnetic flux leakage (MFL) signal is weak, and the number of magnetic sensors installed for defect detection is limited because of the small diameter. In FSWR production workshops, different kinds of machinery work together, deteriorating the power quality and making the spatial electromagnetic environment complex; the weak MFL is thus interfered with further. It is difficult to carry out online nondestructive testing (NDT) of FSWR in the process of manufacturing. In this paper we present a novel MFL method for FSWR NDT in a strong electromagnetic interference environment. We use a three-dimensional finite element method (FEM) to analyze the MFL signals. A simplified magnetic circuit is presented to excite the FSWR; the circuit comprises two half-sized radial magnetizing ring NdFeB magnets, and because there is no need for a magnetic yoke, the device is simple and light. A single Hall sensor is used to measure the flux leakage field. A stable performance power system is designed for the NDT power supply, which is not only resistant to voltage sags, but also has very low output noise. To enhance the signal-to-noise ratio (SNR) of the MFL defects signal, a signal conditioning and processing circuit are designed to enhance the detectability of signals in MFL data. The novel and small FSWR NDT system realizes on-line testing in an environment of strong electromagnetic interference, and for the experiment with a 1.5-mm-diameter wire rope twisted by 19 wires, the minimum damage of a pit on half of a wire can be identified.     

建筑钢结构无损检测技术在中国

钢结构建筑以其抗震、节能、环保、资源再利用、工厂化生产等方面的优势,成为21世纪的建筑发展方向。给保障建筑质量的无损检测技术带来了新的发展机遇。介绍建筑用钢结构无损检测技术的发展历程、应用技术、检测标准、市场需求以及人员培训等概况,揭示出钢结构无损检测事业的广大发展空间。     

在役钢丝绳漏磁检测信号波形分析与应用

在钢丝绳定量无损检测中,检测信号经过放大、滤波等处理后由计算机采集和判别,但计算机自动判别的结果有时和钢丝绳实际情况有一定的出入,如何减小探伤差异、对检测仪检测出的波形进行具体的分析、甄别和判断尤为重要,本文从应用的角度给予了详细分析。     

国内外帘线钢盘条夹杂物检验方法的介绍

围绕国内外帘线钢盘条的夹杂物检验方法,对国内外4种主要典型帘线钢盘条夹杂物检验方法进行了详细介绍及比较,了解了4种检验方法的技术特点,总结了帘线钢盘条夹杂物检验方法的核心要点,尤其对这4种检验方法中所涉及的试样取样面积、夹杂物的类型名称、光学显微镜下不同类型夹杂物的特征形貌进行了识别,阐明了做好帘线钢盘条夹杂物检验和质量控制的价值和意义。     

预应力钢丝缠绕厚壁缸筒三维模型和平面应力模型分析

本文给出预应力钢丝缠绕有限元分析的三维模型和轴截面平面应力模型两种模拟方法。以80MPa内压的50MN预应力钢丝缠绕液压缸为算例进行有限元模拟,将钢丝层简化为六层圆筒,分别施加预应力和边界条件,两种模型均能得到相同的计算结果。但轴截面平面应力模型计算效率更高,结果更容易收敛。在求解方法处理上,将各钢丝层预应力按一个载荷步施加;将每层钢丝载荷工况定义为一个载荷步文件,后一载荷步文件删除前一载荷步载荷,采用载荷步文件法求解,按工况组合的方法将这些载荷步计算的结果叠加在一起;以及采用多载荷步方法计算。三种方法得到了相同的结果。     

拉丝过程中温升对高碳钢丝扭转性能的影响

设计了一系列的模拟试验,研究了拉丝过程中温升对高碳钢丝扭转性能的影响,确定了钢丝扭转性能恶化的临界回火温度为140℃。三维原子探针分析结果表明:渗碳体中的碳原子在回火过程中发生溶解且在铁素体中局部偏聚,聚集的碳原子对位错运动起到了钉扎作用,降低了铁素体的塑性,这是钢丝扭转性能下降的根本原因。     

提高高线焊丝钢日产量的措施

结合生产实践,分析了影响高线焊丝钢日产量的原因,提出了用光学校正仪校正上线导卫、改造冷却水压及水管、校正冷却水喷射角度、优化精轧机组内轧件堆拉关系减小张力等措施,使高线焊丝钢日产量从812 t/d提高到1 015 t/d。     

铜包钢接触线坯连续挤压包覆成形的实验研究

采用连续挤压包覆法生产铜包钢接触线坯 ,是连续挤压技术的一次飞跃 ,铜能成功包覆在钢芯周围的关键是成形模具结构 ,本文通过实验研究 ,探讨了不同模具结构对铜包钢线坯成形的影响 ,分析了包覆成形失败的原因 ,并得到了优化的模具工艺参数 ,为铜包钢接触线坯的连续挤压包覆生产提供了技术依据     

Corrosion monitoring system design for coating wire of steel in ocean

The monitoring system design used in anti-corrosion of coating wire of steel in ocean were concerned. A corrosion monitoring system adapting to corrosion observation of coating wire of steel was introduced in details, including design and choice of software and hardware. This system will play an important role in the collection, procession, demonstration, deposition and accident alarm of corrosion data of oceanic coating wire of steel.     

Nondestructive inspection of delamination in IC packages by high-frequency microwaves

Delamination in IC packages was detected by microwaves. An open-ended coaxial line sensor was employed to couple microwave signals with the package and the package was scanned in two perpendicular directions on a plane parallel to the package. A microwave image was created by measuring the phase of the effective reflection coefficient at the aperture of the coaxial line sensor. A high-frequency microwave was used to obtain a higher spatial resolution. The image obtained from the microwave measurement shows almost the same features as that of a scanning acoustic tomograph. The delamination was detected significantly without a coupling medium. This indicates that microwave imaging is a promising technique for the integrity assessment of IC packages.     

红外热波无损检测序列图像的增强方法

提出了将数据文件显示为红外热波序列图像的方法，即数据映射法，以及一种便于观测试件缺陷的红外热波序列图像增强方法。上述方法能使图像反差增大，同时反映出缺陷点和正常点的不同时刻信号值的不同变化，并以此作为判断被检件是否存在缺陷的依据。     

Nb-V微合金化高碳钢在弹性盖板针布用钢丝上的运用

通过对比添加Nb前后72B钢丝的显微组织、拉伸曲线、弯曲次数分析了钢丝的基本性能变化。结果表明,与72B钢丝相比,添加Nb后钢丝成品的晶粒度从12.5~13级升高至14~14.5级;屈服强度从1745.8 MPa提升至2108 MPa, 提高了约20.7%;抗拉强度从1930.7 MPa提升至2209.5 MPa, 提升了14.4%;断裂前的弯曲次数从1041次增加到1335次,增加了28.2%。说明钢丝在盖板针布的工作环境下具备更好的耐磨性,可以显著提高盖板针布的使用寿命。通过现场试验的验证,新材料钢丝制成的盖板针布的寿命提升了约30%。     

不锈钢药芯焊丝立焊性的分析与评价

利用汉诺威分析仪对4种不同配方的不锈钢药芯焊丝的立焊性能进行了电弧参数测试,分析焊接电流、电弧电压、短路时间的概率密度分布及它们的均方差与电弧稳定性和熔滴过渡的关系.结果表明,焊接电流、电弧电压及短路时间t1的均方差越小,有效短路过渡次数的比率越大,则焊丝熔滴短路过渡的均匀性和稳定性越好,飞溅也越小,立焊效果越好,对药...     

一种热强钢堆焊焊条在轧机备件上的应用

介绍了一种热强钢堆焊焊条的堆焊工艺要求、堆焊层特性。并阐述了这种焊条在热剪剪刃、轧机导板头、球墨无限冷硬铸铁轧辊堆焊等方面的应用情况。     

大规格82B钢盘条的冬季时效行为

研究了?12.5 mm规格82B钢盘条在北方冬季-15～-23℃条件下自然时效0～30 d后的力学性能变化情况,并进行了不同的人工时效试验.结果表明:82B钢盘条的抗拉强度与时效没有明显的关系;自然时效0～10 d后其断面收缩率呈明显上升趋势,10～30 d断面收缩率趋于稳定;盘条下线后立即在200℃保温2 h进行人工...     

Fatigue life improvements of the AISI 304 stainless steel ground surfaces by wire brushing

The surface and subsurface integrity of metallic ground components is usually characterized by an induced tensile residual stress, which has a detrimental effect on the fatigue life of these components. In particular, it tends to accelerate the initiation and growth of the fatigue cracks. In this investigation, to deliberately generate compressive residual stresses into the ground surfaces of the AISI 304 stainless steel (SS), wire brushing was applied. It was found that under the experimental conditions selected in this investigation, while the surface roughness was slightly improved by the brushing process, the surface residual stress shifted from a tensile stress (σ_‖=+450 MPa) to a compressive stress (σ_‖=−435 MPa). On the other hand, the work-hardened deformation layer was almost two times deeper after wire brushing. Concerning the fatigue life, an improvement of 26% in terms of endurance limit at 2×10⁶ cycles was realized. Scanning electron microscope (SEM) observations of the fatigue fracture location and size were carried out to explain the fatigue life improvement. It was found that the enhancement of the fatigue strength could be correlated with the distribution and location of the fatigue fracture nucleation sites. Concerning the ground surfaces, it was seen that the fatigue cracks initiated at the bottom of the grinding grooves and were particularly long (150–200 μm). However, the fatigue cracks at the brushed surfaces were shorter (20–40 μm) and appeared to initiate sideways to the plowed material caused by the wire brushing. The results of the wire-brushed surface characterization have shown that significant advantages can be realized regarding surface integrity by the application of this low-cost process compared to shot peening.     

西部某油田不锈录井钢丝断裂原因分析

针对一起不锈录井钢丝断裂失效事故,采用化学成分分析、金相分析、力学性能测试、扫描电镜分析和能谱分析等检测手段,系统研究了该钢丝断裂失效机理,研究结果表明：该钢丝材质为奥氏体镍铬合金,其在使用过程中遇到高温,导致局部组织发生再结晶并形成过烧组织,使得晶界强度降低,进而断裂。     

H82B钢盘条冬季控冷工艺

冬季低温脆断是高碳钢盘条的普遍问题,对盘条及下游客户拉丝生产造成了严重影响。使用传统斯太尔摩控冷工艺生产的H82B钢盘条常常因心部马氏体、网状渗碳体超标及塑性不达标造成判次,这种现象在冬季尤为明显。通过改进斯太尔摩线控冷工艺等措施,明显改善了盘条的金相组织和力学性能,缩短了冬季自然时效时间,减少了冬季脆断现象。最后阐述了优化控冷工艺的原理。     

钢纤维用盘条表面氧化铁皮的控制研究

钢纤维用盘条表面氧化铁皮厚度和结构对其拉拔前的机械除鳞有较大的影响。为此,研究了不同吐丝温度和冷却工艺下盘条表面的氧化铁皮厚度和结构,结果表明：吐丝温度越高（860 ℃增加到890 ℃）,生成的FeO层越厚（22 μm）;冷却速率越快（05 ℃/s增加到1.5 ℃/s）,生成的Fe3O4层越薄（12 μm）。当吐丝温度为880 ℃、冷却速率为1.5 ℃/s时,氧化铁皮厚度较薄（总厚度15 μm）,致密度较高（FeO：Fe3O4厚度比为4∶1）,易于机械除鳞和拉拔。