LIU Zheng-jian
,
REN Shan
,
ZHANG Jian-liang
,
LIU Wei-jian
,
XING Xiang-dong
,
SU Bu-xin
钢铁研究学报(英文版)
In order to effectively recycle resource for the benefit of the global environment, the utilization of waste plastics as auxiliary injectant for blast furnaces is becoming increasingly important. Combustion kinetics of plastics-coal blends with 0, 10%, 20% and 40% waste plastics (WP) are investigated separately by thermogravimetric analysis (TGA) from ambient temperature to 900 ℃ in air atmosphere. These blends are combusted at the heating rates of 5, 10 and 20 ℃/min. The results indicate that, with the increase of waste plastics content, the combustion processes of blends could be divided into one stage, two stages and three stages. The waste plastics content and heating rates have important effects on the main combustion processes of blends. With the increase of waste plastics content, the ignition temperature and the final combustion temperature of blends tend to decrease, while the combustion reaction becomes fiercer. With the increase of the heating rate, the ignition temperature, the mass loss rate of the peaks and the final combustion temperature of blends combustion tend to increase. The Flynn-Wall-Ozawa (FWO) iso-conversional method is used for the kinetic analysis of the main combustion process. The results indicate that, when the waste plastics content varied from 0 to 40%, the values of activation energy increase from 126.05 to 184.12 kJ /mol.
关键词:
waste plastics
,
anthracite
,
co-combustion kinetics
,
TGA
,
iso-conversional method
LIN Yin-he
,
GUO Zhan-cheng
,
TANG Hui-qing
,
REN Shan
,
LI Jing-wei
钢铁研究学报(英文版)
Micro-fluidized bed reactor is a new research method for the reduction of iron ore fines. The reactor is operated as a differential reactor to ensure a constant gas concentration and temperature within the reactor volume. In order to understand the dynamic process of the reduction reaction in micro-fluidized bed, a series of kinetic experiments were designed. In the micro-fluidized bed, the use of shrinking core model describes the dynamic behavior of reduction of iron ore. And the apparent activation energy is calculated in the range of 700-850 ℃ while the initial atmosphere is 100% content of CO.
关键词:
iron ore reduction
,
micro-fluidized bed
,
dynamics
ZHANG Jian-liang
,
REN Shan
,
SU Bu-xin
,
LIN Yin-he
,
LONG Shi-gang
钢铁研究学报(英文版)
In order to study the combustion characteristics of waste tire particle (WTP), pulverized coal (PC) and their mixture, the contents of CO, CO2 and O2 of off-gas during the combustion of WTP, PC and mixture under the condition of rich oxygen by 0-4% in blast and at 1250 ℃ were measured simultaneously using synthetically infrared analyzer, and then the corresponding combustion ratio was calculated and compared. The results showed that the burning rate of WTP reached approximately 57%, which is much higher than that of PC (only about 18%) in the initial 650 s in fresh air, and then the increase of combustion rate of PC is faster than that of WTP; the combustion rate of PC improved remarkably with the addition of WTP. Meanwhile, the combustion rates of all these materials improved with the increase of oxygen content.
关键词:
blast furnace
,
waste tire particle
,
pulverized coal
,
combustion ratio
张麦仓
,
董建新
,
曾燕屏
,
谢锡善
,
罗子健
金属学报
利用热力耦合有限元程序FORMT,对PM René 95合金中等尺寸(外径尺寸约为630 mm)涡轮盘的等温锻造工艺进行了模拟式设计.结果表明,采用TZM钼基合金模具,在1050℃以接近10-3s.的应变速率进行闭式模锻和开式模锻,模具材料均能满足使用要求,且开式模锻设备最大载荷不超过31×103kN;采用K21合金模具,在1000℃以相同条件等温成形,模具材料因变形热效应及边界摩擦引起温升而失效且所需设备吨位相对较大.
关键词:
PM
,
null
,
null
,
null
张麦仓
,
董建新
,
曾燕屏
,
谢锡善
,
罗子健
金属学报
doi:10.3321/j.issn:0412-1961.2002.10.022
利用热力耦合有限元程序FORMT,对PM René 95合金中等尺寸(外径尺寸约为630 mm)涡轮盘的等温锻造工艺进行了模拟式设计.结果表明,采用TZM钼基合金模具,在1050℃以接近10-3s.的应变速率进行闭式模锻和开式模锻,模具材料均能满足使用要求,且开式模锻设备最大载荷不超过31×103kN;采用K21合金模具,在1000℃以相同条件等温成形,模具材料因变形热效应及边界摩擦引起温升而失效且所需设备吨位相对较大.
关键词:
PM René 95合金,等温锻造,热力耦合有限元,模拟式工艺设计
付锐
,
陈希春
,
任昊
,
冯涤
航空材料学报
doi:10.3969/j.issn.1005-5053.2011.3.002
自行设计开发了适合工业化生产高纯净,低偏析,无宏观缺陷铸锭的电渣重熔连续定向凝固技术(ESR-CDS)的设备和工艺,利用该技术成功制备了直径为φ150mm的René88DT合金定向凝周铸锭.采用XRD测试了定向凝固柱状晶的生长取向,结果表明,ESR-CDS René88DT铸锭柱状晶择优生长方向为<100>系晶向;ERS-CDS铸锭与传统ESR铸锭相比,枝晶组织生长方向保持一致,二次枝晶臂均匀细小,元素偏析程度低,且晶间一次析出相呈颗粒状,尺寸细小;等温热压缩实验结果表明,ESR-CDS René88DT合金热压缩试样在1100℃,0.0-50.1s-1应变速率下可达到70%以上压缩变形量并获得均匀细小的动态再结晶组织;ESR-CDS René88DT合金铸锭经等温锻造制备出了φ170mm×73mm的饼坯件,锻压变形量超过70%,饼坯件除上下两端的变形死区外均发生了动态再结晶,晶粒尺寸约50μm.
关键词:
电渣重熔连续定向凝固
,
热变形
,
动态再结晶
李晓
,
董建新
,
张丽娜
,
张麦仓
,
胡尧和
,
谢锡善
,
国为民
金属学报
经不同固溶时效处理的PM René 95合金于650℃分别在蠕变、保载5和90 s疲劳载荷条件下进行了裂纹扩展速率实验.结果表明,相同热处理制度下,疲劳保载时间越长,裂纹扩展速率越高;相同载荷条件下,增加一次高温固溶并缓冷,有利于降低合金的裂纹扩展速率,且固溶温度越高裂纹扩展速率越低;1200℃一次固溶缓冷并于1160℃二次固溶热处理比1140℃一次固溶的裂纹扩展速率约降低一个数量级;基体晶粒尺寸适当加大,强化相粒子γ′c数量增加、形状趋于田字形,有利于降低裂纹扩展速率.
关键词:
René
,
null
,
null
李晓
,
董建新
,
张丽娜
,
张麦仓
,
胡尧和
,
谢锡善
,
国为民
金属学报
doi:10.3321/j.issn:0412-1961.2001.10.012
经不同固溶时效处理的PM René 95合金于650℃分别在蠕变、保载5和90 s疲劳载荷条件下进行了裂纹扩展速率实验.结果表明,相同热处理制度下,疲劳保载时间越长,裂纹扩展速率越高;相同载荷条件下,增加一次高温固溶并缓冷,有利于降低合金的裂纹扩展速率,且固溶温度越高裂纹扩展速率越低;1200℃一次固溶缓冷并于1160℃二次固溶热处理比1140℃一次固溶的裂纹扩展速率约降低一个数量级;基体晶粒尺寸适当加大,强化相粒子γ′c数量增加、形状趋于田字形,有利于降低裂纹扩展速率.
关键词:
René 95粉末高温合金,裂纹扩展速率,热处理
