Q235B 薄板坯高温塑性的研究

根据Gleeble1500热/应变模拟试验机测试的CSP薄板坯连铸工艺生产的成分(%)为0.16~0.20C,0.020~0.060Al_t Q235B钢的70 mm ×1 500 mm薄板坯600~1400℃热塑性曲线,得出连铸坯第Ⅲ脆性区为700~900℃,如在此温度范围矫直,铸坯易产生裂纹。通过扫描电镜分析断口形貌和电子探针的成分分析,得出形变诱导铁素体呈网状析出和奥氏体在低温区域析出氮化物(AlN)导致铸坯脆化。     

2205双相不锈钢连铸坯的高温组织和高温力学性能

对2205双相不锈钢连铸坯进行高温短时拉伸试验,分析了抗拉强度、断面收缩率随温度的变化情况。观察了试验温度为1 300、1 050、950、850℃下试样的高温组织及断口形貌。结果表明,在1 150～1 350℃温度范围内,双相不锈钢试样具有很好的塑性;在1 000～1 100℃时,较高的应变速率抑制了软化作用的进行,使双相不锈钢出现第Ⅱ脆性温度区,同时试样中存在的疏松和细小析出物进一步加剧了裂纹的发展。第Ⅲ脆性区产生的原因是由于在奥氏体晶界上析出了氮化物、碳氮化物等细小析出物造成晶界脆化。     

1.2%Si冷轧无取向电工钢铸坯高温延塑性研究

采用Gleeble1500应力/应变热模拟试验机对1.2%Si冷轧无取向电工钢铸坯进行了高温延塑性测试;在1 300～600℃的试验温度下,得到了试样的热塑性和强度曲线,并通过对不同温度下试样的断口形貌及脆性区夹杂物的观察,分析其在脆性温度区域的脆性断裂的机理。研究结果表明:1.2%Si冷轧无取向电工钢铸坯在1.0×10-3/s应变速率下,测试温度在1 300～600℃范围内,存在1 220℃以上的第Ⅰ脆性温度区域和780～600℃的低塑性温度区域。1.2%Si冷轧无取向电工钢780～600℃时塑性降低的原因:一方面是动态再结晶困难;另一方面是铁素体低温区域发生的氮化物(AlN)及硅铝酸盐的析出产生的晶界脆化。     

含铌Q460C连铸坯高温热塑性研究

在邯钢gleeble-3500热/力模拟试验机上,针对Q460C连铸坯进行了高温热塑性测试研究.结果表明:1000～1300℃为塑性温度区间;650～950℃为第Ⅲ脆性温度区,在此区间,沿奥氏体晶界析出膜状铁素体抗拉能力较低,晶界处存在夹杂物及微合金元素的析出物是钢的热塑性降低的主要原因,极易导致连铸坯产生裂纹缺陷.     

钙处理对集装箱板钢铸坯高温延塑性影响研究

测定了集装箱板钢的高温力学性能 ,并比较钙处理和合金元素对其的影响。试验结果表明在1× 10 - 3 / s应变速率下 ,集装箱板钢连铸坯在凝固温度～ 6 0 0℃间存在两个脆性温度区域。细小的脆性夹杂物Ca S优先析出并聚集在奥氏体晶界 ,使晶界进一步脆化 ,造成钙处理钢铸坯试样在 80 0～ 90 0℃时的延塑性低于未经钙处理钢试样。为提高耐大气腐蚀能力而添加的合金元素 P对其高温力学性能没有造成明显不利影响。同时结果表明集装箱板钢试样的零强度温度 (ZST)在 144 0～ 145 0℃左右 ,零延性温度 (ZDT)在 140 0～ 1410℃左右。     

氮微合金化HRB500E连铸坯高温力学性能的研究

为了优化氮微合金化钢HRB500E的连铸冷却配水工艺,保证铸坯质量,采用Gleeble-1500D热模拟试验机测定了铸坯的高温力学性能,并对试样断口组织形貌进行了显微观察与分析,讨论了其在不同温度区间的断裂机理。研究表明:在应变速率为1.4×10-3/s时,铸坯第Ⅲ脆性温度区间出现在675~750℃,脆断主要原因是铁素体在奥氏体晶界析出、晶界处Mn S的偏析和大量V(C,N)的析出;铸坯未出现第Ⅱ脆性温度区,在1 000℃左右断裂方式为穿晶断裂;第Ⅰ脆性温度区在1 300℃以上,断裂方式为晶间断裂,主要原因是O,S,P在晶界富集促进形成液膜。     

SS400含硼钢连铸坯的高温力学性能

 为了避免和减轻SS400含硼钢连铸坯表面裂纹,采用Gleeble-1500热模拟试验机对SS400含硼钢连铸坯的高温力学性能进行了测试,获得其在650～1350 ℃范围内热延塑性和高温强度的特性。试验结果表明,SS400含硼钢连铸坯的高温强度较低,且其高温强度随温度的升高而下降。SS400含硼钢的塑性区间仅在1 000～1 100 ℃温度范围内,该温度范围内试样的断面收缩率均大于90%;SS400含硼钢的低塑性区间较宽,第Ⅲ脆性温度区间为700～950 ℃,主要原因是硼在晶界的偏聚以及BN等第二相粒子在晶界析出后脆化晶界;局部区域的重熔也降低了SS400含硼钢在1 150～1 250 ℃温度区间内的塑性。     

含铌微合金高强度钢Q345C连铸坯的热塑性

 通过Gleeble-2000 试验机研究了Q345C钢连铸坯的高温热塑性。利用扫描电镜、金相显微镜、透射电镜观察了第Ⅰ、Ⅲ脆性温度区内拉伸试样断口部位的显微组织及形貌,分析了动态再结晶、相变、析出物等对微合金化钢高温延塑性的影响。结果表明：在1×10-3/s应变速率下, Q345C钢存在两个脆性温度区,即第Ⅰ脆性区（1200～1300℃）和第Ⅲ脆性区（600～875℃）,无第Ⅱ脆性区出现;最高塑性出现在1050℃左右,断面收缩率（Z）达到85.8%;在第Ⅲ脆性区,沿奥氏体晶界析出膜状铁素体抗拉能力较低,晶界处存在夹杂物以及微合金元素的析出物,是钢的热塑性降低的主要原因。     

钢中残余元素对连铸圆坯纵裂的影响

使用Gleeble机测定了不同残余元素含量的连铸圆坯试样的高温力学性能,结果表明:Cu当量(Cu+10Sn)＝0.32 %的试样在925～1 000 ℃,特别是在950 ℃的热塑性显著降低;扫描电镜和俄歇检验发现,此温度下试样为沿晶断裂,在奥氏体晶界有Sn偏析.分析连铸生产条件认为,如拉速较低,结晶器内初生坯壳温度处于此高温脆性区,圆铸坯将可能产生纵裂.     

Q345C连铸坯高温热塑性的研究

在Gleeble-2000热模拟机上,针对Q345C钢连铸坯,进行了高温热塑性测试.分析了Q345C钢试样的断口性质及显微组织与塑性的关系.研究了第Ⅲ脆性区的脆化原因.实验结果表明:在1 300～600℃区间存在两个脆性温度区,其中第Ⅲ脆性温度域为600～850℃,其断面收缩率RA范围是60.23%～29.61%;指出了该钢种在实际生产条件下适宜的铸坯矫直温度.     

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.