GCr15冷轧辊早期断裂失效分析EI

采用光学金相和电子探针分析仪等分析手段，对ＧＣｒ１５冷轧辊早期断裂进行了分析。结果表明：断裂源并不位于宏观断口上，而是位于应力集中的辊颈键槽根部，硫化物在此聚集并沿轴向分布，导致冷轧辊在工作中发生断裂。该辊颈的显微组织很不均匀，加快了裂纹的扩展。     

冷轧辊断裂事故分析

本文采用光学金相和扫描电镜等手段，对冷轧辊过早失效断裂进行了分析，结果表明，辊颈Ｒ１．５部位因镀铬不当引起表面腐蚀缺陷，构成了疲劳断裂源，导致辊颈盍中瞬时脆断，而材质致密度较差，断裂源位于应力集中部位，也是导致轧辊超前失效断裂不可忽视的因素。同时提出了预防轧辊断裂的措施。     

冷轧镀锌生产中光整机工作辊粘锌的控制措施

在带钢连续热镀锌生产中,由于光整机工作辊粘锌而更换新辊,是生产中常见的情况。本文介绍了在生产实际中光整机工作辊粘锌的主要原因,并简要地进行了分析,提出了相应的控制措施,以提高工作辊使用周期,降低生产成本。     

冷连轧机D．H．支承辊剥落失效原因分析

对某冷连轧机使用的D．H．合金铸钢支承辊的带状剥落失效进行了分析，对失效支承辊的化学成分，气体含量，断口形貌，显微组织及力学性能等进行了检验。认为，显微组织不符合支承辊材质要求，残余奥氏体和有害气体含量严重超标，是造成支承辊发生带状剥落失效的主要原因。     

冷轧辊剥落原因分析

Cr3锻钢冷轧工作辊在冷处理过程中，辊身端部发生剥落。通过化学成分、显微组织和断口形貌的检验分析，认为电渣重熔时钢锭内部产生的夹渣使得轧辊在淬火过程中形成裂纹，在随后的冷处理时裂纹失稳扩展造成轧辊剥落。     

汽车前轴辊锻模的失效形式与修复方法

从材料的选择、结构设计、制造工艺、热处理工艺以及模具的安装维护等方面分析汽车前轴辊锻模的主要失效形式（断裂、磨损、变形等）产生的原因,并提出相应的改进措施和修复方法。     

GCr15冷轧管机孔型模的失效分析

对ＧＣｒ１５冷轧管机孔型模早期剥落、上机炸裂及淬火开裂的原因进行了试验和分析，结果表明，钢中严重的白点和网状碳化物及淬火组织不良是导致材料早期失效的原因，据此，提出了改进措施。     

银纳米线透明导电薄膜的失效机理研究

银纳米线透明导电薄膜材料作为新兴的无铟电极材料, 以其优越的光电性能和力学柔韧性, 在显示器件、触控面板、太阳能电池、智能加热和电磁屏蔽等领域崭露头角, 吸引越来越多的来自科研界及产业界的关注。然而, 银纳米线透明导电薄膜在应用中面临着较为严重的稳定性问题, 主要表现为容易被痕量含硫气体腐蚀, 在300 ℃以上的温度下纳米线出现断裂和球形化等结构失稳现象, 在紫外光照条件下腐蚀及球形化加剧, 在加载电场条件下出现离子迁移并产生孔洞及断裂现象。本文详细介绍了以上各种失效现象, 分析了失效的微观机制, 介绍了解决各种失效现象的具体措施。银纳米线透明导电薄膜失效行为的研究, 有助于进一步推动该材料的实际应用进程。     

Cr12MoV钢冷轧工作辊缺陷分析

采用磁粉探伤、化学分析及金相检验等方法对Cr12MoV钢冷轧工作辊粗磨后表面呈现的螺旋形波纹进行了检测分析。结果表明，冷轧工作辊在粗磨过程中因磨削过热，使其表层的回火马氏体转变为回火托氏体，改变了表面应力状态，导致表面出现裂纹。提出了预防措施。     

铝合金导电管腐蚀失效原因分析

用于高压隔离开关的铝合金导电管存在着严重而普遍的腐蚀问题,危及高压隔离开关的正常运行.运用能谱分析、金相分析和电子探针等技术对铝合金导电管的破损原因进行了分析.结果表明,导电管存在着高度定向的纵向显微组织和局部脱溶,Cu,Fe等有害元素的相在晶界处大量连续析出,造成晶界附近出现贫化区,由于导电管的工作环境为近海海洋大气带,其中含有大量的侵蚀性阴离子,众多因素是导电管的腐蚀成因.其腐蚀过程为先在表面发生点蚀,然后发展成晶间腐蚀,在晶间腐蚀和内应力的协同作用下最终开裂形成剥蚀.     

Inconel 625合金波纹管失效分析

采用化学分析,透射电子显微镜(TEM)、X射线光电子能谱仪(XPS)和扫描电子显微镜(SEM)等微观测试手段对失效波纹管化学成分、力学性能、断口腐蚀产物及断口微观形貌进行综合分析。研究结果表明,波纹管的失效是材料在腐蚀性环境下局部高应力处首先发生高温氧化、硫化腐蚀,产生疲劳裂纹源,在交变应力的作用下发生腐蚀疲劳而造成的。通过降低腐蚀和波纹管应力可以防止或减轻腐蚀疲劳发生,延长波纹管使用寿命。     

三相分离器失效分析研究

分析了三相分离器失效的原因，认为造成该分离器失效的主要原因为沟状腐蚀。阐述了沟状腐蚀发生的原因及过程，最后提出了防止该类分离器失效的措施及方法。     

泵体端盖螺栓失效分析

以某企业HWD100-400燃料油泵端盖的紧固螺栓为研究对象,介绍了紧固螺栓的服役条件及常见失效形式,并通过宏观形貌分析、化学成分测试、金相组织分析、硬度测试分析等分析方法,分析了该紧固螺栓断裂的原因。结果表明,紧固螺栓在安装时预紧力过大,而产生的应力集中造成该紧固螺栓失效。     

轧辊断裂原因分析

轧辊在经调质热处理后的校直过程中辊颈发生断裂。采用宏观检验、金相检验和化学成分分析等方法对轧辊断裂的原因进行了分析。结果表明：由于断口处存在较为严重的共晶碳化物和较大尺寸的氧化铝夹杂物形成了应力集中点,导致辊颈在调质热处理后的校直过程中发生断裂。     

Failure Analysis on Diesel-Engine Valve Springs

A diesel engine used in a truck had a trouble when servicing. Inspection indicated that four exhaust and intake valve springs and two exhaust and intake valves were fractured. Fractographic studies indicated that fatigue fracture is the main failure mechanism for all of the four valve springs. Under the action of the maximum normal stress, the fatigue crack initiated in the spring wire of coil 1.3-1.5 from the upper end of the spring. This region is also the most damaged location by contact friction wear. The fracture of the intake and exhaust valve stems also suggests fatigue failure probably as a result of the failure of the associated valve springs.     

A View on the General Practice in Engineering Failure Analysis

Analysis of engineering failures is a complex process that requires information from personnel having expertise in many areas. From the information gathered, a failure analyst tries to discover what was fundamentally responsible for the failure. This fundamental cause is termed the “root cause” and helps in the determination of the sequence of events that led to the final failure. Root cause analysis also helps in finding solutions to the immediate problem and provides valuable guidelines as to what needs to be done to prevent recurrence of similar failures in future. However, experience suggests that most failure analyses fall short of this goal. A significant number of failure analysts incorrectly use the term “root cause” when what they really establish is the primary cause of failure or simple physical cause. This paper examines a few service failures to demonstrate that the term root cause is not adequately understood.     

翅片管路焊接接头断裂原因分析

通过KYKY2800扫描电镜等技术手段对翅片管路焊接接头进行失效分析。分析表明,焊缝与2#环管的焊趾处存在有不连续的咬边,造成应力集中;在交变应力的作用下于咬边处产生微裂纹,并沿一定方向扩展（同时材料的不均匀性也为裂纹的扩展提供了有利条件）,直至最后疲劳断裂,造成失效。最后提出了预防措施。     

Failure Prevention in Design Through Effective Catalogue Utilization of Historical Failure Events

The science of failure prevention relies heavily on the experience of personnel on a project. As the nation is about to face a tremendous decline in the experienced workforce due to the baby boomer generation’s retirement, it is critical to begin focusing on capturing their knowledge. Cataloging and communicating the knowledge of potential failures is critical to prevent engineering disasters. Many companies have adopted failure-reporting systems that allow them to record their engineering failures to promote failure prevention. While recording this information is vital to learning from past mistakes, often the information is not stored so that engineers and designers can easily recall this valuable linguistic information and use it to improve designs. Therefore, more effective systems for cataloging and utilizing corporate memory of recorded failure events are needed. This article presents the design of a computational linguistic database to support the failure prevention tool, the risk in early design (RED) method. RED promotes failure prevention by identifying failure risks as early as the conceptual phase of product design, where impacts of failure prevention are greatest. It uses a database populated by historical failure event information to present specific areas that are at risk of failure in a product.     

Premature Failure in Orthopedic Implants: Analysis of Three Different Cases

The increasing lifetime of the population on a world-wide scale over the last decades has led to a significant growth in the use of surgical implants for replacement of bones and teeth in affected patients. Other factors, such as scientific-technological development and more frequent exposure of individuals to trauma risk, have also contributed to this general trend. Metallic materials designed for applications in surgical implants, no matter whether orthopedic or dental, must show a group of properties in which biocompatibility, mechanical strength, and resistance to degradation (by wear or corrosion) are of primary importance. In order to reach these aims, orthopedic materials must fulfill certain requirements, usually specified in standards. These requirements include chemical composition, microstructure, and even macrographic appearances. In the present work, three cases of implant failure are presented. These cases demonstrate the most frequent causes of premature failure in orthopedic implants: inadequate surgical procedures and processing/design errors. Evaluation techniques, including optical and scanning electron microscopy (SEM), were used to evaluate macroscopic and microstructural aspects of the failed implants, and the chemical composition of each material was analyzed. These evaluations showed that design errors and improper surgical procedures of outright violation of standards were the cause of the failures.