影响挤压模具使用寿命的因素分析

提高模具使用寿命是降低铝型材生产成本的重要因素 ,它与产品断面形状 ,以及模具设计、制造、使用和挤压工艺条件、挤压锭坯成分、锭坯组织状态、设备性能等有关。     

H68黄铜扁锭热轧表面裂纹的初步研究

本文采用金相、扫描电镜及化学分析法,研究了H68黄铜扁锭热轧表面裂纹的成因。分析结果表明,造成H68黄铜扁锭热轧表面裂纹的直接原因,是Pb,Bi等微量元素在晶界上偏聚所致。     

7075扁锭在镦粗过程中表面裂纹的原因分析

牌号为7075的铝合金扁锭,经加热镦粗后,发现扁锭表面和侧面共有3处很深的裂纹,裂纹大约深为8~20mm。经化学成分分析、宏观组织、显微组织以及扫描电镜断口分析,结果表明:失效扁锭的化学成分符合GB/T3190-2008的要求,低倍组织除裂纹外没有发现其它冶金缺陷,断口表面发现有氧化现象,显微组织未过烧。可判断失效扁锭开裂是因固-液区内的金属塑性低,熔体结晶时体积收缩产生拉应力,当拉应力超过当时的金属温度下的强度或收缩率大于伸长率时则产生裂纹,裂纹属于热裂纹即铸造裂纹。     

7075合金扁锭裂纹的工艺研究

本文介绍了７０７５合金扁锭裂纹的成因、形态和性质，并从成分控制　、应力调整、熔体净化等方面提出了防止裂纹的措施。     

5083铝合金大规格扁锭铸造热裂纹缺陷的研究

分析了5083铝合金520mm×1660mm规格扁锭铸造工艺中出现热裂纹缺陷的原因,并通过试验研究了不同铸造温度对铸造热裂纹的影响,解决了铸锭热裂纹缺陷;重点分析了铸锭热裂纹倾向及预防措施。     

关于6111铝合金扁铸锭裂纹的研究

针对6111铝合金铸锭裂纹的产生原因如化学成分对裂纹缺陷的影响、细化剂Ti对裂纹缺陷的影响、熔体质量对裂纹缺陷的影响、铸造工艺处方对裂纹缺陷的影响、水质及水分布对裂纹缺陷的影响进行了分析。提出了降低缺陷的相应措施，如化学成分的合理设计、熔体质量控制要求、铸造工艺处方设定、水质及水分布监控。经过实践6111铝合金扁铸锭裂纹得到有效控制。     

水冷模铸纯铝扁锭裂纹的防止方法

对于水冷模扁锭裂纹的防止,国内尚未得到满意的方法。笔者采取多种试验方法,经过近几年来的摸索,终于找到了一种防止铸锭裂纹的有效方法。     

扁锭横裂纹的形成原因

1989年韶关特殊钢公司为优化产品结构,提高效益,决定生产扁锭加工成板材。但由于经验不足和条件不具备等原因,扁锭表面出现了裂纹,出现率严重时占生产支数的     

抗挤毁油井套管用钢管裂纹分析

通过对衡钢生产的抗挤毁油井套管表面裂纹进行分析,得出裂纹是钢中的残余有害元素造成,并经轧制,调质,回火后使裂纹扩大暴露的结论。据此,结合生产现场现有设备技术条件,提出了减少裂纹的工艺改进措施。     

大型扁型钢锭模的裂纹分析及结构优化设计

针对大型灰铸铁扁型钢锭模早期裂纹报废问题，采用计算机模拟计算技术对ＦＺ２５ｔ钢锭模使用过程的温度场、热应力和裂纹敏感系数的变化过程进行了数值计算分析，并优化了结构设计。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.