SUS304+Q235B复合板卷冷轧工艺技术研究

以SUS304+Q235B热轧复合板卷为试验材料,利用单机架冷轧可逆轧机生产线,对SUS304+Q235B复合板卷进行了冷轧轧制工艺研究,分析了SUS304+Q235B复合卷冷轧变形规律及冷轧工艺控制技术,探讨了SUS304+Q235B复合板冷轧工艺参数,制定出一套适合生产实际的工艺方案。结果表明:单机架冷轧机组生产的SUS304+Q235B复合板界面结合良好,厚度尺寸和力学性能满足用户使用要求。     

304+Q235B不锈钢复合板晶间腐蚀研究

采用对称组坯的方式,热轧法生产304+Q235B不锈钢复合板,在热轧完成后,对自然空冷和ACC冷却的两种钢板取样进行检测分析,对比两种冷却条件下304不锈钢晶间腐蚀的情况。结果表明,在ACC冷却条件下,复合板表面不锈钢未产生晶间腐蚀。     

热轧管线用不锈钢复合板组织和性能研究

研究了热轧管线用304不锈钢+X65管线钢复合板的组织形貌、断口特征和性能。结果表明复合板组织理想,X65管线钢基板以针状铁素体组织为主,304不锈钢覆层为奥氏体组织;覆层与基板实现了良好的结合,剥离界面呈现均匀分布的等轴韧窝形貌;复合板力学性能良好,具有较低屈强比和较高的抗剪强度。     

316L/Q345R热轧复合板界面组织演变及性能

利用扫描电子显微技术结合能谱分析对316L/Q345R热轧复合板结合界面组织及元素扩散情况进行了检测,通过热力学计算分析了界面附近碳的分布规律,并测量了结合界面的显微硬度与剪切强度。结果表明,结合界面碳钢一侧存在约50μm的铁素体带,而不锈钢侧存在约100μm的元素扩散影响区;不锈钢中铬、镍等元素向碳钢中扩散,碳钢中碳元素向不锈钢中扩散;复合板界面剪切强度为373 MPa,明显高于标准规定的210 MPa,略低于Q345R与316L剪切强度和的1/2(379 MPa)。     

不锈钢复合板界面组织形貌

界面微观组织形貌严重影响不锈钢复合板的界面结合强度及其抗蚀性能,为此,采用氩气保护轧制复合法制备了SUS304不锈钢/普碳钢复合板,对复合板界面区显微组织、元素扩散以及嵌合现象进行了观察分析。结果表明,不锈钢/普碳钢两种金属在界面区域发生了不同程度的相互嵌合,随着轧制道次增加,嵌合程度加深,界面孔洞减少,界面结合强度提高。在界面附近,碳元素穿越界面向不锈钢侧发生扩散,碳化物相主要分布在晶界上,XRD及TEM检测结果表明,富铬碳化物相为M23C6型碳化物。不锈钢复合板剪切强度随压下率增加而增大,经过总压下率为74.5%的轧制后,剪切强度达到361 MPa。     

Q235/304碳钢-不锈钢复合板界面结合的有限元模拟

应用MARC软件对304不锈钢(%:17～19Cr、8～11Ni)/Q235碳钢(%:0.14～0.22C)复合板前5道次往复热轧过程(变形率%:3.4、10.4、25.0、37.8、49.4)进行有限元模拟,得出Q235钢和304不锈钢在界面处的应力和应变分布。模拟结果表明,在两种材料都进入塑性变形状态时,界面处法向应力值达到或超过304不锈钢界面温度下的变形抗力,且两种材料应变平均值的差值≤0.01时即可复合,该模拟结果与生产试验结果一致;这说明使用小的单道次变形率,大的累积变形率可获得结合良好的碳钢/不锈钢复合板。     

真空热轧不锈钢复合板界面结合行为的研究

为了研究真空热轧不锈钢复合板的结合行为,本文以热轧304不锈钢/Q345低碳钢复合板为研究对象,通过剪切试验及组织分析等手段研究了变形量及真空度对不锈钢复合板结合性能的影响规律.结果表明,轧制总变形量从35%增加到75%之后复合板的剪切强度大约可增加100 MPa.真空度降低会导致结合界面氧化程度增加,进而降低复合板的结合性能,当真空由0.1 Pa变为20 Pa时,界面氧化物的比例由约10%提高到约50%,剪切强度由440 MPa降低到了350 MPa左右.最后根据试验结果提出了热轧不锈钢复合板的结合行为.     

包覆浇铸高硼不锈钢复合板的变形协调性

包覆浇铸后的复合铸坯虽然已具有冶金结合,但热轧过程中,道次变形量若确定不合理将在界面处产生附加应力,附加应力值的大小将影响热轧后复合板的界面结合情况。应用ABAQUS有限元软件对包覆浇铸304不锈钢/高硼不锈钢/304不锈钢复合铸坯的热轧过程进行了有限元模拟,有限元模拟结果显示,当道次变形量大于17%时,覆层及芯层变形协调性变差,复合板界面将遭到破坏。实际热轧试验验证了有限元模拟结果的正确性,为包覆浇铸复合铸坯的热轧提供了有利的工艺参数。     

蒙乃尔金属粉末与钢板复合轧制技术研究

采用自主设计研发制作的高刚度二辊冶金粉末350 mm试验轧机,采取"冷轧+烧结+热轧"的工艺方法,实现了蒙乃尔400金属粉末与Q235B钢板复合轧制,并对轧制出的复合板界面进行金相分析、SEM、EDX等检测,结果表明,蒙乃尔400粉末与Q235B界面实现了冶金结合,且界面致密度良好。     

热处理对316L/Q235复合板组织与力学性能的影响

 对热轧不锈钢复合板热处理前后状态进行了对比研究,利用扫描电镜对显微组织进行了观察和成分分析,利用维氏硬度计测量了试样硬度,通过剪切、拉伸试验对试样的力学性能进行了研究。结果表明,真空热轧复合板能实现良好复合,碳钢侧为铁素体和珠光体组织;不锈钢侧为奥氏体组织。热处理后试样界面结合性能提高,试样剪切强度、屈服强度和抗拉强度都相应提高。高温阶段快速冷却＋低温阶段缓慢冷却的热处理制度适用于316L/Q235不锈钢复合板热处理。     

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.