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文章速递Effect of nanosized NbC precipitates on hydrogen-induced cracking of high-strength low-alloy steel 认领
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作者 En-dian Fan Shi-qi Zhang +3 位作者 Dong-han Xie Qi-yue Zhao Xiao-gang Li Yun-hua Huang 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2021年第2期249-256,共8页
We investigated the effect of nanosized NbC precipitates on hydrogen-induced cracking(HIC)of high-strength low-alloy steel by conducting slow-strain-rate tensile tests(SSRT)and performing continuous hydrogen charging ... We investigated the effect of nanosized NbC precipitates on hydrogen-induced cracking(HIC)of high-strength low-alloy steel by conducting slow-strain-rate tensile tests(SSRT)and performing continuous hydrogen charging and fracture analysis.The results reveal that the HIC resistance of Nb-bearing steel is obviously superior to that of Nb-free steel,with the fractured Nb-bearing steel in the SSRT exhibiting a smaller ratio of elongation reduction(Iδ).However,as the hydrogen traps induced by NbC precipitates approach hydrogen saturation,the effect of the precipitates on the HIC resistance attenuate.We speculate that the highly dispersed nanosized NbC precipitates act as irreversible hydrogen traps that hinder the accumulation of hydrogen at potential crack nucleation sites.In addition,much like Nb-free steel,the Nb-bearing steel exhibits both H-solution strengthening and the resistance to HIC. 展开更多
关键词 nanosized NbC precipitates high-strength low-alloy steel hydrogen-induced cracking slow-strain-rate tensile hydrogen charging
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基于航空金属材料腐蚀的我国大气环境分区 认领
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作者 张腾 张胜 +2 位作者 何宇廷 马斌麟 张天宇 《装备环境工程》 CAS 2020年第5期1-9,共9页
目的针对我国服役飞机的腐蚀问题,实现飞机结构日历寿命的分区预测与精细化管理。方法收集我国大气环境17个典型地区的气象环境数据,编制各地区的气候、化学环境总谱,并根据腐蚀电荷当量原理,使用铝合金、合金钢两种材料的折算系数,将... 目的针对我国服役飞机的腐蚀问题,实现飞机结构日历寿命的分区预测与精细化管理。方法收集我国大气环境17个典型地区的气象环境数据,编制各地区的气候、化学环境总谱,并根据腐蚀电荷当量原理,使用铝合金、合金钢两种材料的折算系数,将各地区的大气环境向标准潮湿空气作用时间进行折算。基于系统聚类的方法,根据大气腐蚀的差异性,将17个典型地区进行分类,确定各分区的划分标准和我国大气腐蚀分区个数,并综合考虑当前文献中可查的其他地区数据资料与我国气候、降水、大气污染的分布情况,对我国大气环境进行腐蚀分区。结果根据铝合金、合金钢的腐蚀特征量,可将我国大气环境划为5个分区。绘制了我国大气环境腐蚀分区图,给出了各分区的环境特点、地理位置分布和代表城市。结论应用我国大气环境分区结果,可以直观掌握我国飞机不同服役环境的腐蚀严酷程度,为编制加速腐蚀环境谱、评定飞机结构日历寿命、制定针对性的维护计划和飞行计划奠定基础。 展开更多
关键词 铝合金 合金钢 腐蚀 大气环境分区 标准潮湿空气 系统聚类
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高速钢组焊刀具热处理工艺研究 认领
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作者 张瑜 赵兴德 《新技术新工艺》 2020年第9期10-12,共3页
通过开展常见的高速钢(刃部)和合金钢(柄部)相组合的刀具的热处理工艺研究,探索影响高速钢组焊刀具综合性能的热处理过程影响因素。结果表明,对焊刀具由于柄部和刃部材料不同,需进行分段热处理,同时刃部需要进行等温淬火。刃部采用W6Mo5... 通过开展常见的高速钢(刃部)和合金钢(柄部)相组合的刀具的热处理工艺研究,探索影响高速钢组焊刀具综合性能的热处理过程影响因素。结果表明,对焊刀具由于柄部和刃部材料不同,需进行分段热处理,同时刃部需要进行等温淬火。刃部采用W6Mo5Cr4V2Al和W2Mo9Cr4V2Co8材料,热处理后综合使用性能良好,均能满足生产使用要求。柄部采用合金钢可以有效减少刀具变形量。 展开更多
关键词 高速钢 合金钢 组焊刀具 热处理
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低合金耐磨铸钢绞刀齿的研制 认领
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作者 魏昂 鲁宁斌 +3 位作者 李日新 黄睿 焦修勤 李柏 《热加工工艺》 北大核心 2020年第6期50-52,共3页
设计了一种中碳低合金铸钢,生产的挖岩用绞刀齿经淬火和低温回火热处理后,本体硬度大于49 HRC、冲击功大于20 J、抗拉强度大于1600 MPa。试样的金相组织基本为回火板条马氏体,冲击断口形貌以韧窝为主,属于韧性断裂。在三体磨损试验下,... 设计了一种中碳低合金铸钢,生产的挖岩用绞刀齿经淬火和低温回火热处理后,本体硬度大于49 HRC、冲击功大于20 J、抗拉强度大于1600 MPa。试样的金相组织基本为回火板条马氏体,冲击断口形貌以韧窝为主,属于韧性断裂。在三体磨损试验下,本体试样的失重明显小于国内同类产品的。经实船挖掘某处风化岩,表明其使用寿命优于国内其他产品的,达到了进口产品的水平。 展开更多
关键词 低合金 铸钢 绞刀齿
60AT1做长心轨的固定型合金钢辙叉设计 认领
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作者 郑会锋 《山西建筑》 2020年第10期134-135,共2页
主要介绍了60AT1合金钢钢轨做长心轨的60 kg/m钢轨12号固定型合金钢组合辙叉的结构特点,并针对辙叉结构进行了检算分析。辙叉满足线路使用要求,且结构简单,各种零部件易于加工,制造安装方便,生产周期短。
关键词 固定型 合金钢 辙叉设计
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脉冲激光精微烧蚀合金钢表面热影响研究 认领
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作者 明兴祖 申警卫 +1 位作者 金磊 明瑞 《应用激光》 CSCD 北大核心 2020年第1期42-49,共8页
基于脉冲累积效应对纳秒激光精微烧蚀18Cr2Ni4WA钢进行传热分析,并在MATLAB中进行温度场仿真;采用波长为532 nm、脉宽为8 ns的纳秒脉冲激光对18Cr2Ni4WA钢进行烧蚀实验,分析了脉冲累积下热传导过程;采用单元素法分析激光能量密度、脉冲... 基于脉冲累积效应对纳秒激光精微烧蚀18Cr2Ni4WA钢进行传热分析,并在MATLAB中进行温度场仿真;采用波长为532 nm、脉宽为8 ns的纳秒脉冲激光对18Cr2Ni4WA钢进行烧蚀实验,分析了脉冲累积下热传导过程;采用单元素法分析激光能量密度、脉冲数对靶材表面几何形貌的影响规律,并将靶材表面损伤区域分为激光烧蚀区域和热影响区域。实验结果表明:烧蚀凹坑半径随脉冲数的增加而增大,但半径的增大不是持续的;在激光单脉冲能量40 mJ、10个脉冲数下,靶材表面的机械划痕因质量流动而去除,达到相对平整的形貌。本文对探索合金钢烧蚀特性有参考意义。 展开更多
关键词 脉冲激光 激光烧蚀 合金钢 表面热影响 表面质量
等温淬火对激光增材制造12CrNi2合金钢组织和拉伸性能的影响 认领
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作者 亢红伟 董志宏 +3 位作者 张炜 谢玉江 迟长泰 彭晓 《激光与光电子学进展》 CSCD 北大核心 2020年第9期107-114,共8页
采用激光增材制造技术制备了12CrNi2合金钢,其主要由铁素体基体和少量残余奥氏体组成,沉积层间热影响区边界明显,与沉积层内部组织相比,其内铁素体粗化而奥氏体减少。经过等温淬火热处理后,沉积态合金钢组织不均匀性消除,同时,强度亦得... 采用激光增材制造技术制备了12CrNi2合金钢,其主要由铁素体基体和少量残余奥氏体组成,沉积层间热影响区边界明显,与沉积层内部组织相比,其内铁素体粗化而奥氏体减少。经过等温淬火热处理后,沉积态合金钢组织不均匀性消除,同时,强度亦得到明显提高。还报道了贝氏体组织形貌特征随等温淬火温度与时间变化的演化规律及其对成形合金钢屈服/抗拉强度与延伸率的影响机制,提出了获得综合力学性能最优的热处理条件。 展开更多
关键词 激光光学 激光增材制造 合金钢 等温淬火 显微组织 力学性能
钼在合金钢冶炼中的应用现状和发展前景 认领
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作者 张朝晖 李东林 +3 位作者 邢相栋 刘世锋 张光曦 鲁慧慧 《钢铁研究学报》 CAS CSCD 北大核心 2020年第1期1-8,共8页
综述了目前国内外钼在合金钢冶炼中的应用现状,介绍了传统钼铁生产工艺,并明确了传统工艺能耗较高、污染严重的弊端。系统分析了采用工业氧化钼直接合金化生产含钼合金钢的方法和优势,针对该工艺存在的氧化钼易挥发等关键问题进行总结,... 综述了目前国内外钼在合金钢冶炼中的应用现状,介绍了传统钼铁生产工艺,并明确了传统工艺能耗较高、污染严重的弊端。系统分析了采用工业氧化钼直接合金化生产含钼合金钢的方法和优势,针对该工艺存在的氧化钼易挥发等关键问题进行总结,阐述了国内外该领域的研究进展和解决途径,即利用在氧化钼合金化过程中配加CaO等碱金属或碱土金属的方式能够有效抑制氧化钼挥发。最后,进一步分析了钼在不锈钢、低合金钢、工模具钢及其他合金钢中的应用现状和研究进展,提出了钼在合金钢冶炼中的未来发展方向。 展开更多
关键词 钼铁 工业氧化钼 合金钢
镁合金与钢异质材料焊接的研究进展 认领
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作者 宋刚 赵爽 +1 位作者 李涛涛 刘黎明 《机械工程学报》 EI CAS CSCD 北大核心 2020年第8期1-12,共12页
镁合金是最轻的金属类工程结构材料,钢仍是目前应用最广泛的金属材料,镁合金与钢形成结构件能够充分发挥材料“物尽其用”的优势,在航空航天、汽车等领域具有广阔的应用前景。镁与钢不仅物理和化学性能差异巨大,而且两者属于典型的不反... 镁合金是最轻的金属类工程结构材料,钢仍是目前应用最广泛的金属材料,镁合金与钢形成结构件能够充分发挥材料“物尽其用”的优势,在航空航天、汽车等领域具有广阔的应用前景。镁与钢不仅物理和化学性能差异巨大,而且两者属于典型的不反应难固溶异质材料,实现镁合金与钢高性能连接是焊接领域研究热点及面临的极大挑战。基于此,详细总结与分析了国内外镁合金/钢焊接结合模式、焊接方法、焊接接头组织及力学性能等方面的研究进展,并阐述了镁合金/钢异质材料焊接接头界面错配研究现状。最后,结合现有研究进展和应用需求,提出镁合金/钢异质材料焊接未来可能的研究方向,旨在为后续研究提供参考与借鉴。 展开更多
关键词 镁合金 焊接方法 力学性能 界面组织
Effect of position and force tool control in friction stir welding of dissimilar aluminum-steel lap joints for automotive applications 认领
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作者 M.Wasif Safeen P.Russo Spena +3 位作者 G.Buffa D.Campanella A.Masnata L.Fratini 《先进制造进展:英文版》 SCIE CAS CSCD 2020年第1期59-71,共13页
Widespread use of aluminum alloys for the fabrication of car body parts is conditional to the use of appropriate welding methods,especially if dissimilar welding must be performed with automotive steel grades.Friction... Widespread use of aluminum alloys for the fabrication of car body parts is conditional to the use of appropriate welding methods,especially if dissimilar welding must be performed with automotive steel grades.Friction stir welding(FSW)is considered to be a reasonable solution to obtain sound aluminum-steel joints.In this context,this work studies the effects of tool position and force control in dissimilar friction stir welding of AA6061 aluminum alloy on DC05 low carbon steel in lap joint configuration,also assessing proper welding parameter settings.Naked eye and scanning electron microscopy(SEM)have been used to detect macroscopic and microscopic defects in joints,as well as to determine the type of intermixture between aluminum and steel.The joint strength of sound joints has been assessed by shear tension test.Results point out that tool force control allows for obtaining joints with better quality and strength in a wider range of process parameters.A process window has been determined for tool force conditions to have joints with adequate strength for automotive purposes. 展开更多
关键词 AA6016 aluminum alloy Dissimilar materials DC05 low carbon steel Friction stir welding(FSW) Welding parameters
叉车合金钢轴头的水淬可控冷却工艺 认领
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作者 肖结良 黄诚 麻先银 《金属热处理》 CAS CSCD 北大核心 2020年第12期110-113,共4页
分析了水的冷却特性、水淬可控冷却原理,利用水淬可控冷却和普通水淬两种方法对35CrMo合金钢叉车轴头进行了调质处理,并对调质后轴头的组织和微裂纹进行了检测。结果表明:水淬可控冷却调质轴头组织为细小均匀的回火索氏体,无微裂纹,硬... 分析了水的冷却特性、水淬可控冷却原理,利用水淬可控冷却和普通水淬两种方法对35CrMo合金钢叉车轴头进行了调质处理,并对调质后轴头的组织和微裂纹进行了检测。结果表明:水淬可控冷却调质轴头组织为细小均匀的回火索氏体,无微裂纹,硬度适中,符合技术要求;而普通水淬调质后轴头工件有1/3出现裂纹。可见,对水的起始温度、水和工件的质量比以及冷却时间加以控制,能够对形状复杂的合金钢轴头实现可控冷却,从而获得满意的淬火效果,实现清洁化热处理。 展开更多
关键词 轴头 合金钢 水淬 可控冷却
钛/钢异种金属激光焊接接头微观组织及数值模拟研究 认领
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作者 杨胜 李军兆 +1 位作者 刘一搏 孙清洁 《电焊机》 2020年第8期101-105,I0008,共6页
为实现TC4钛合金与316L不锈钢异种金属的优质连接,采用Cu作为中间层进行激光焊接。研究表明,采用Cu中间层能够有效抑制界面脆性Ti-Fe金属间化合物的产生。随着焊接速度的增加,接头强度显著提高,TC4钛合金与焊缝界面主要为连续的Ti-Fe化... 为实现TC4钛合金与316L不锈钢异种金属的优质连接,采用Cu作为中间层进行激光焊接。研究表明,采用Cu中间层能够有效抑制界面脆性Ti-Fe金属间化合物的产生。随着焊接速度的增加,接头强度显著提高,TC4钛合金与焊缝界面主要为连续的Ti-Fe化合物层和非连续的Ti-Fe、Ti-Cu化合物层,厚度约为60μm。有效地降低了接头脆性、抑制裂纹,缓解了接头应力,能够获得良好的钛/钢异种金属激光焊接接头。 展开更多
关键词 钛合金 不锈钢 激光焊接 数值模拟 组织
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改进型耻骨联合分离记忆合金内固定器的生物力学特征 认领
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作者 周君 宫玉锁 +1 位作者 李盛华 朱艳国 《中国组织工程研究》 CAS 北大核心 2020年第36期5764-5767,共4页
背景:记忆合金自身具有独特形状记忆性能及良好的组织相容性,目前被制作成各种内固定器广泛用于微动关节及骨折部位的手术治疗。目的:探究改进型耻骨联合分离记忆合金内固定器的生物力学特性。方法:取10具成人骨盆标本,建立耻骨联合分... 背景:记忆合金自身具有独特形状记忆性能及良好的组织相容性,目前被制作成各种内固定器广泛用于微动关节及骨折部位的手术治疗。目的:探究改进型耻骨联合分离记忆合金内固定器的生物力学特性。方法:取10具成人骨盆标本,建立耻骨联合分离损伤模型,随机分2组固定:观察组复位后以改进型耻骨联合分离记忆合金内固定器固定,对照组复位后以动力加压钢板固定,采用万能生物材料试验机进行生物力学测试,记录耻骨联合水平、前后与垂直方向的相对位移。结果与结论:①两组模型均无松动及内固定断裂;②不同载荷下观察组水平方向的位移均小于对照组(P<0.05);③不同载荷下观察组前后方向的位移均小于对照组(P <0.05);④不同载荷下观察组垂直方向的位移均小于对照组(P <0.05);⑤结果表明,改进型耻骨联合分离记忆合金内固定器对抗水平及前后方向的拉力优于动力加压钢板,对抗垂直剪切力优于动力加压钢板。 展开更多
关键词 植入物 内固定 记忆合金 固定 钢板 力学 生物力学
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激光摆动模式对铝/钢焊接接头成形特征及组织、强度的影响 认领 被引量:1
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作者 李军兆 刘一搏 +4 位作者 孙清洁 陶玉洁 张清华 靳鹏 冯吉才 《中国激光》 EI CAS CSCD 北大核心 2020年第4期133-140,共8页
铝、钢金属在物理化学性质上的巨大差异使得铝/钢异种接头的优质连接成为焊接领域的难点。采用摆动激光热源实现了6061铝合金和316L不锈钢搭接接头的良好连接,研究了激光摆动模式、摆动频率对接头成形质量、界面组织结构及拉剪强度的影... 铝、钢金属在物理化学性质上的巨大差异使得铝/钢异种接头的优质连接成为焊接领域的难点。采用摆动激光热源实现了6061铝合金和316L不锈钢搭接接头的良好连接,研究了激光摆动模式、摆动频率对接头成形质量、界面组织结构及拉剪强度的影响。结果表明:摆动激光能够增加铝/钢界面的连接面积,减小接头的熔深,有效抑制焊缝中的气孔、裂纹等缺陷;同时,摆动激光能使界面温度均匀并增强对熔池的搅拌作用,降低界面处的冶金反应,有效抑制界面脆硬金属间化合物的产生;摆动激光焊接接头的界面组织主要为Fe(Al)固溶体及少量弥散分布的针状FeAl3相;摆动激光焊接接头的最大拉剪强度可达117.5 N/mm,相比于常规激光焊接接头提高了约45%,接头断裂位置为不锈钢与焊缝交界处。 展开更多
关键词 焊接技术 摆动激光焊接 铝合金 不锈钢 微观组织 强度
Effect of process parameters on the microstructure and properties of laser-clad FeNiCoCrTi0.5 high-entropy alloy coating 认领 被引量:1
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作者 Ying Zhang Teng-fei Han +1 位作者 Meng Xiao Yi-fu Shen 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2020年第5期630-639,共10页
FeNiCoCrTi0.5 coatings with different process parameters were fabricated by laser cladding. The macro-morphology, phase, microstructure, hardness, and wear resistance of each coating were studied. The smoothness and d... FeNiCoCrTi0.5 coatings with different process parameters were fabricated by laser cladding. The macro-morphology, phase, microstructure, hardness, and wear resistance of each coating were studied. The smoothness and dilution rate of the FeNiCoCrTi0.5 coating generally increased with the increase of specific energy(Es), which is the laser irradiation energy received by a unit area. FeNiCoCrTi0.5 coatings at different parameters had bcc, fcc, and Ti-rich phases as well as equiaxed, dendritic, and columnar structures. When Es increased, the size of each structure increased and the distribution area of the columnar and dendritic structures changed. The prepared FeNiCoCrTi0.5 coating with the Es of 72.22 J·mm-2 had the highest hardness and the best wear resistance, the highest hardness of the coating reached HV 498.37, which is twice the substrate hardness. The average hardness of the FeNiCoCrTi0.5 coating with the Es of 72.22 J·mm-2 was 15.8% higher than the lowest average hardness of the coating with the Es of 108.33 J·mm-2. The worn surface morphologies indicate that the FeNiCoCrTi0.5 coatings exhibited abrasive wear. 展开更多
关键词 high-entropy alloy COATING 45 steel LASER CLADDING microstructure WEAR resistance
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Effect of adhesive on laser-arc hybrid welding of aluminum alloy to high-strength steel joint 认领
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作者 Hong-yang Wang Yu-qing Ma Li-ming Liu 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2020年第9期1099-1107,共9页
Aluminum alloy 6061 and high-strength steel Q460 were joined by laser-arc-adhesive hybrid welding technology successfully.A Cu alloy interlayer was added between Al alloy and high-strength steel.The effect of the adhe... Aluminum alloy 6061 and high-strength steel Q460 were joined by laser-arc-adhesive hybrid welding technology successfully.A Cu alloy interlayer was added between Al alloy and high-strength steel.The effect of the adhesive on laser-arc-adhesive hybrid welding of Al alloy to high-strength steel was discussed.The optical microscope,scanning electron microscope and electron probe micro-analysis were applied to observe the microstructural evolution and phase transition at Al-Fe interface of laser-arc-adhesive hybrid welded joints.The results showed the maximum tensile shear strength of the joint without adhesive was 256 MPa.After adding adhesive,the maximum tensile shear strength reached 282 MPa.The combination of the mechanical bonding and the metallurgical effect could improve the mechanical performances.The shape of the joint in Al alloy changed into a canine-like morphology.There was no porosity in welds because the molten pool of Al alloy and the special keyhole phenomenon of laser welding provided a channel for the decomposed gas to escape from fusion zone. 展开更多
关键词 Laser-arc welding Aluminum alloy High-strength steel Cu interlayer ADHESIVE
一种尾部铝合金装饰条结构设计 认领
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作者 刘绍娟 《时代汽车》 2020年第24期121-122,共2页
文章依据新市场需求及现有不锈钢装饰条的外观质量缺陷,设计一款新的适合装配环境要求、外观质量要求及市场需求的尾部铝合金装饰条。
关键词 尾部装饰条 铝合金 不锈钢
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Principle for obtaining high joint quality in dissimilar friction welding of Ti-6Al-4V alloy and SUS316L stainless steel 认领
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作者 Huihong Liu Yo Aoki +2 位作者 Yasuhiro Aoki Kohsaku Ushioda Hidetoshi Fujii 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第11期211-224,共14页
Ti-6Al-4V alloy(Ti64)and SUS316 L stainless steel rods were dissimilarly friction welded.Especially focusing on the detailed observation of interface microstructural evolution during the friction welding(FW),the relat... Ti-6Al-4V alloy(Ti64)and SUS316 L stainless steel rods were dissimilarly friction welded.Especially focusing on the detailed observation of interface microstructural evolution during the friction welding(FW),the relationship between the processing conditions,weld interface microstructure,and mechanical properties of the obtained joints were systematically investigated to elucidate the principle for obtaining a high joint quality in the FW of Ti64 and SUS316L.A higher friction pressure produced a lower welding temperature in the FW,hence suppressing the thick intermetallic compound layer formation.However,hard and brittle Ti64/SUS316L mechanically mixed layers generally formed especially at the weld interface periphery due to the high temperature increasing rate,high rotation linear velocity and high outward flow velocity of the Ti64.These harmful layers tended to induce the cracks/voids formation at the weld interfaces hence deteriorating the joints’mechanical properties.The rotation speed reduction and liquid CO2 cooling during the entire processing decreased the temperature increasing rate,rotation linear velocity and outward flow velocity of the Ti64 at the weld interface periphery.Therefore,they suppressed the formation of the harmful mechanically mixed layers,facilitated the homogeneous and sound interface microstructure generation,and finally produced a high-quality dissimilar joint in the FW of Ti64 and SUS316L. 展开更多
关键词 Friction welding Titanium alloy Stainless steel Microstructure formation mechanism Mechanically mixed layers
Visualization of microstructural factors resisting the crack propagation in mesosegregated high-strength low-alloy steel 认领
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作者 Shuxia Wang Chuanwei Li +2 位作者 Lizhan Han Haozhang Zhong Jianfeng Gu 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第7期75-84,共10页
While relationship between fracture mechanism and homogeneous microstructures has been fully understood,relationship between fracture mechanism and inhomogeneous microstructures such as the mesosegregation receives le... While relationship between fracture mechanism and homogeneous microstructures has been fully understood,relationship between fracture mechanism and inhomogeneous microstructures such as the mesosegregation receives less attention as it deserves.Fracture mechanism of the high-strength low-alloy(HSLA)steel considering the mesosegregation was investigated and its corre s ponding micro structure was characterized in this paper.Mesosegregation re fers to the inhomogeneous distribution of alloy elements during casting solidification,and leads to the formation of positive segregation zones(PSZ)and negative segregation zones(NSZ)in ingots.The fracture surface of impact sample exhibits the quasi-cleavage fracture at-21℃,and is divided into ductile and brittle fracture zone.Meanwhile,the PSZ and NSZ spread across ductile and brittle fracture zone randomly.In ductile fracture zone,micro-voids fracture mechanism covers the PSZ and NSZ,and higher deformation degree is shown in the PSZ.In brittle fracture zone,secondary cleavage cracks are observed in both PSZ and NSZ,but present bigger size and higher quantity in the NSZ.However,some regions of the PSZ still present micro-voids fracture mechanism in brittle fracture zone.It reveals that the microstructures in the PSZ exhibit a higher resistance ability to crack propagation than that in the NSZ.All observations above provide a better visualization of the microstructural factors that resist the crack propagation.It is important to map all information regarding the fracture mechanism and mesosegregation to allow for further acceptance and industrial use. 展开更多
关键词 High-strength low-alloy steel Heavy forgings Mesosegregation Inhomogeneous microstructures Fracture mechanism
The effect of crack tip environment on crack growth behaviour of a low alloy steel at cathodic potentials in artificial seawater 认领
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作者 Yong Li Zhiyong Liu +2 位作者 Endian Fan Zhongyu Cui Jinbin Zhao 《材料科学技术:英文版》 SCIE EI CAS CSCD 2020年第19期119-131,共13页
The environment at crack tip and its effect on the crack growth behaviour of low alloy steel-E690 steel were studied at cathodic potentials in artificial seawater.The results showed that the micro environment at crack... The environment at crack tip and its effect on the crack growth behaviour of low alloy steel-E690 steel were studied at cathodic potentials in artificial seawater.The results showed that the micro environment at crack tip and crack growth behaviour were related to the electrochemical reactions at crack tip,which were affected by the stress state and applied potentials.The crack tip environment was acidified under cyclic loading,resulting from the crack tip anodic dissolution reaction and corresponding hydrolysis reaction.Because of the hydrogen evolution and the inhibited anodic dissolution inside the crack,the crack tip p H increases as the cathodic potential decreases.The effect of cathodic potentials on the electrochemical reactions caused the variation of the hydrogen content,which influenced the crack growth rate because the crack growth behaviour was controlled by hydrogen embrittlement mechanism.This resulted in a fact that with the negative decrease of potential,the crack growth rate first decreased and then increased,with the minimum rate at-0.75 V.And the crack growth path exhibited transgranular fracture. 展开更多
关键词 Low alloy steel Stress state Cathodic potential Crack tip environment Crack growth behaviour
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