钢锭模使用前后的微观组织与残余应力分析

文章从两方面研究了灰口铸铁大型钢锭模(9.8吨和7.1吨)的失效原因。一是组织上的变化,以确凿的事实和显微照片证明了:使用后的钢锭模从内壁开始,珠光体严重的球化、石墨片氧化,在石墨片周围形成疏松的硅锰氧化物区,使内壁的力学性能首先降低,在反复使用、冷热急剧变化的恶劣条件下,是造成内壁裂纹源的重要原因。二是研究了钢锭模残余应力的变化规律,对铸造态,时效态和退火态的钢锭模分别做了残余应力的测定和分析。结果表明;铸造态残余应力最大,时效态和退火态残余应力变小。但文章认为,致使钢锭模失效报废的原因,主要是循环使用于冷热急剧变化条件下的热应力作用的结果,与残余应力的关系不大。对钢锭模经退火或时效可以提高寿命的传统看法提出了质疑,认为根据不足,此工艺完全可以省去。     

稀土高炉铁水大扁钢锭模使用过程中化学成分的变化

通过解剖废钢锭模,较详细地研究了微量稀土高炉铁水大扁钢锭模在使用过程中化学成分的变化,它直接影响了基体组织、性能的变化及其使用寿命。掌握钢锭模在使用过程中化学成分的变化来缓解基体组织及性能的变化,对钢锭模使用寿命的研究给予定量的认识。     

4.5t蠕墨铸铁钢锭模在使用过程中温度场的测量

钢锭模在使用过程中的温度是模型设计、选用材质、确定工艺流程和冷却方式所必须依据的重要参数.本文描叙了在钢锭模使用过程中沿x、y、z三个方向对19个点连续测温的结果,测置中距钢锭模内壁最近的测温点是沿模子高度方向上的中心部位,距模子内壁5mm.前言1980年12月冶金部召开的"稀土在铸钢铸铁中应用会议"决定以"蠕墨铸铁、球墨铸铁钢锭模、轧辊、球铁铸管"为1981年科研计划的重点.研究蠕墨铸铁、球墨铸铁钢锭模的目的是提高钢锭模的使用寿命.钢锭模的结构、材质、使用工艺流程、冷却方式等因素对钢锭模使用寿命有直接影响.使用过程中钢锭模的温度分布情况则是进行钢锭模结     

铸铁钢锭模在使用中组织的变化

钢锭模的使用性能一般是由其在反复高温加热中组织的变化程度而定。但资料中只介绍了钢锭模破损后组织的质的变化。根据这些数据很难购钢锭模使用中破损过程的程度。因此,研究钢锭模在使用初期沿模壁厚度组织的质和量变化情况是有意义的。本研究是用重6吨无底方形钢锭模,它由下列化学成分的铸铁铸成:C4.3％,Si1.13％,Mn0.83％,S0.05％,P0.065％,Ti0.05％。试验钢锭模在组合铸型中浇注,铸型由粘土砂芯和粘土衬砖底板及周围有金属型壁或金属涂层组成。金属用下注法浇注,用光学高温计测出注温为1453K,注后6.5小     

提高钢锭模的寿命

正如众所周知,钢锭模的寿命取决于它的类型(板坯、初轧坯、型坯有底模,上小下大的,无底的),浇钢方法(上注,下注),钢锭模材质(高炉生铁或化铁炉生铁),制造工艺,结构及使用条件等。上述每项因素都对钢锭模使用寿命的增加有着强烈的影响。在长期对铸铁物理机械性能及组织特征的理论和实践研究的基础上,确定了与化学成分,热稳定性的质和量的关系,制订了有簿片状石墨的灰铸铁最好的化学成分范围,用它浇注钢锭模最合适。高炉生铁要求其成分为:C3.9～4.2％,Si0.7～0.9％,Mn0.7～1.0％,S≤0.035％,P<0.15％,在铸型中浇注时要求得到珠光     

关于5308A鋼錠模的使用寿命

本文叙述了影响灰口铸铁钢锭模寿命的因素及改进方向,阐明了钢锭模产生掉皮的机构,并认为改善使用条件比调整成分和组织对钢锭模寿命影响更大,改变爐料配比对钢锭模的耐用性有利。文中认为:细化石墨和强化基体、及时地脱锭和及时冷却钢锭模是能减少掉皮现象的主要措施。     

用铝合金化提高球墨铸铁钢模锭的使用寿命

球墨铸铁用铝合金化可以大大提高冲击韧性、热稳定性和抗氧化性,因而可提高球墨铸铁钢锭模的使用寿命。苏联北方钢管厂对生产无缝钢管用钢的钢锭模进行了使用试验其中选择了八个炉号球墨铸铁钢锭模做化学成分与球化率的试验,实际成分见下表(％): 铸铁的成分为0.51～1.60％A1,1.70～1.80％Si,0.065～0.110％Mg(熔炼号1～3)。球状石墨(球化率)为85～100％。含硅量降低到1.02～1.39％(熔炼号4～6),球化率基本不变,但出现了自由渗碳体。当含铝量大于0.8％时,尽管残余含镁量很高,而球化率却显著降低(熔炼号7～8)。另外,又用六个炉号球墨铸铁钢锭模的试样做了有关性能方面的试验。试验结果,成分中含1.02～1.86％Si和0.44～0.60％A1的钢锭模具有     

钢锭模内壁的清理装置

日本钢铁界最近研制成功一种清理钢锭模内壁的新设备。它主要由以下部件构成:门形机台、台车、塔形机架、垂直圆筒、导轨、导向辊、轴承、垂直旋转轴、刷子轴、电动机、钢丝绳卷筒、滑轮、螺杆、联轴节和操作台等。使用该装置清理钢锭模时,首先提升其部件垂直筒,并使门形机台在钢锭模的上方移动。门形机台的移动将带动由弯曲的钢丝绳构成的钢刷,使钢刷沿着钢锭模的内壁旋转。另外,借助于台车的动作,可使钢刷与钢锭模的模壁紧密接触。由于钢刷可沿钢锭模的四壁上下左右自由地移动,因此可迅速而安全彻底地清除掉粘附于钢锭模模壁上的钢渣残留物,并且对钢锭模内壁的转角处也能彻底地进行清理。     

4.5t稀土镁蠕墨铸铁钢锭模的研制

本文叙述了为生产4.5tRe-Mg蠕墨铸铁钢锭模所必须的一系列基本试验:蠕化剂的选择、蠕墨铸铁的机械、物理和铸造性能以及蠕墨铸铁钢锭模的使用寿命.结果指出:根据从钢锭模棱角处取样进行观察,当蠕虫状石墨为20～40％,其余为球状石墨时,钢锭模具有最好的使用寿命,比同类型的灰口铸铁钢锭模寿命提高24％.     

钢锭模内壁早期剥落原因分析及对策

通过对钢锭模内壁早期剥落原因的分析,找出其产生原因,并制定和实施了相应的措施,减少了钢锭模内壁早期剥落的发生,提高了钢锭模的使用寿命。     

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.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.