连铸坯枝晶臂间距检测方法的优化与应用实践

介绍了连铸坯凝固组织中树枝晶臂间距检测方法的优化试验及其应用效果。通过对连铸坯凝固冷却过程的分析及批量数据的采集,确定了测定连铸坯树枝晶臂间距的代表性区域,建立了一种科学测量枝晶臂间距的方法。将该方法应用于连铸圆坯生产检验中,能快速准确地找出铸坯枝晶臂间距随连铸二冷强度变化的规律,采取调整连铸二冷强度的措施,来控制一、二次枝晶臂间距大小,达到了减轻或消除铸坯开裂缺陷、提高连铸质量的目的。     

CSP薄板坯的铸态组织特征研究

对CSP的铸坯组织、化学成分偏析、枝晶间距、气体含量、夹杂物以及轧制过程中的组织变化进行了研究,结果表明:CSP薄板坯的低倍组织在结构上和传统板坯没有本质区别,但薄板坯组织较为细密,柱状晶比较发达,一次枝晶与二次枝晶间距小,化学成分均匀,铸坯全氧含量为28×10-6,氮含量为47×10-6;第一道次轧制后中心部的疏松和偏析明显减轻,树枝晶沿轧制方向弯曲,但没有被打碎;CSP铸坯中大颗粒夹杂物较少,主要是外来的;内生夹杂物主要以含氧化铝和铝酸盐及氧化钙的为多,尺寸基本都在10μm以内,大部分在2～5μm。     

CSP薄板坯的铸态组织及力学性能特征

对CSP的铸坯组织、化学成分偏析、枝晶间距、轧制过程中的组织变化以及薄板的力学性能进行了研究。结果表明：CSP薄板坯的低倍组织在结构上和传统板坯没有本质区别，但薄板坯组织较为细密，柱状晶比较发达；第一道次轧完后中心部的疏松和偏析明显减轻，树枝晶沿轧制方向弯曲，但没有被打碎；CSP工艺生产的HSLC钢的力学性能与微合金化HSLA钢相当。     

水平连铸20钢管坯的铸态组织特征

本文采用金相分析方法研究了碳钢水平连铸管坯铸态组织的一些特征。如初期凝固坯壳组织形貌;树枝晶二次枝间距;以及受工艺、设备等条件的影响而形成的异常组织形态等等。这里所讲的铸态组织,系指用“Stead”试剂显现的树枝晶组织,有些文献称之为一次组织或亚组织。     

连铸参数对高碳钢小方坯二次枝晶间距的影响

通过研究高碳钢小方坯连铸参数对铸坯二次枝晶臂间距的影响发现:采用结晶器电磁搅拌、加大二冷比水量,二次枝晶臂间距减小;过热度升高、拉速增大,二次枝晶臂间距增大.无M-EMS的铸坯接近中心的区域,仍然是枝晶臂发达的柱状晶组织;采用结晶器电磁搅拌,促使铸坯中心区域形成粒状等轴晶组织;随搅拌电流增大,二次枝晶间距明显减小.随二次枝晶臂间距增大,渗透率增加,造成铸坯中心碳偏析加重.     

M_2高速钢连铸坯的凝固组织及质量——高速钢连铸坯内部质量究研之一

本文重点研究了M_2高速钢连铸坯的凝固组织及其内部质量。测定了铸坯中树枝晶二次枝晶臂间距的大小,从而得到了浇注过程中铸坯的平均冷却速度。同时对M_2高速钢连铸坯的非金属夹杂物作了金相形貌的观察和鉴定,证明M_2高速钢连铸坯的表面质量良好,但内部质量不能令人满意,产生严重的V形偏析,铸坯中发现含钙的大型硅酸盐夹杂和含铝的夹杂物。铸坯的等轴晶带较宽:二次枝晶臂间距较小,因而铸坯的凝固组织致密。除中心部分外其它部位的致密程度皆优于模铸M_2高速钢。     

电磁搅拌工艺对模具钢组织和性能的影响

连铸二冷区辊式电磁搅拌能够打断凝固前沿枝晶,破碎的枝晶在剩余钢液中成为弥散等轴晶形核点,扩大铸坯中心等轴晶比例;另一方面,钢液的流动使未凝固钢液成分均匀化,减少中心偏析和疏松。通过对采用电磁搅拌工艺生产的中厚板模具钢进行低倍、硬度及组织分析,研究电磁搅拌工艺对改善模具钢组织和性能产生的影响。     

BOF-LF-CSP工艺生产低碳热轧薄板的组织变化规律

为了弄清BOF-LF-CSP工艺生产低碳钢的组织变化规律,对低碳钢SS400进行了铸态组织、第一轧制道次的形变组织以及成品板卷的组织测试与分析.结果表明：薄板坯铸态组织为较细的枝状晶,铸坯表面层和中心差别很小.经第一道次大压下变形后板坯的晶粒组织得到明显细化,表面至中心区域的晶粒尺寸及硬度存在梯度分布.低碳钢SS400成品薄板的组织很细,平均晶粒尺寸在5μm左右.     

CSP生产线生产Ti微合金化高强耐候钢铸态组织研究

对CSP生产的Ti微合金化高强耐候钢的铸坯组织、化学成分偏析、枝晶间距、夹杂物进行研究,结果表明,CSP生产的Ti微合金化高强耐候钢铸坯的低倍组织在结构上和传统板坯及CSP生产的普通集装箱铸坯相差不大,但高强耐候钢铸坯组织更为细密,一次枝晶间距、二次枝晶间距较普通集装箱铸坯稍小.铸坯中偏析较严重的元素是C、S、P,其它元素偏析较轻.铸坯中大颗粒夹杂物较少,主要是Al、Ti、Ca、S类夹杂物,由于Ti、Ca、S含量较少,夹杂物含量较低.而通过对Al类夹杂物进行分析,发现Al类夹杂物在连铸坯横截面上均匀分布,没有明显的偏聚,夹杂物含量在0.001 4%～0.002 2%波动,符合夹杂物存在特性,波动幅度在正常范围内,铸坯中Al夹杂物大部分粒度在2.5 μm以下.     

连铸坯枝晶组织参数的测定及其应用

介绍了连铸坯凝固的枝晶组织特征、形成机制及定量评定方法。通过对硅钢连铸坯凝固组织比例系数和枝晶间距的测定以及连铸坯低倍组织缺陷的统计分析,确定了凝固组织形态与铸坯成分的关系。分析结果表明,在一定限度内,随Si含量增加,铸坯的一次晶间距加宽,各类低倍组织缺陷大大减少。     

Chinalco Signed Framework Agreement for Strategic Cooperation with Harbin Municipal Government

正Last month,Chinalco signed framework agreement for strategic cooperation with Harbin Municipal Government in Harbin Xiong Weiping,Chairman of Chinalco,said that based on the strategic deployment to build world top-class mining company with the highest growth potential,Chinalco was now concentrating all efforts on making strategic transition and structural adjustment,strategic cooperation with the local governments where     

Jiangxi Promotes Jiangxi Copper Corporation To Become The World's Most Competitive Mining Company

<正>According to the latest info from Jiangxi Province State-owned Assets Supervision and Administration Commission,Jiangxi Copper Corporation was approved to become the first pilot enterprise for deepening reform.Contents of the pilot work is"Three Self"(self expansion,self decision-making,self     

Journal of Rare Earths Contents List of Vol.32(2014)

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Contributions to Baosteel Technical Research wanted

正Baosteel Technical Research,a quarterly journal,which is issued domestically and abroad,is run and sponsored by Baosteel Group Corporation.Baosteel Technical Research mainly reports the achievements in technological innovation,academic research,new product development and industrial equipment improvement by Baosteel.It will continue to follow up on hot topics and serve the company’s technological development and progress.Its readers include experts in     

Ministry of Industry and Information Technology: No Short Term Solution For Our Country’s Excess Nonferrous Metal Smelting Capacity

【正】According to the Ministry of Industry and Information Technology,the Ministry has released the 2013 Operation Report on China’s Industrial Communication Indu...     

Chinalco Signed Framework Agreement for Strategic Cooperation with Gansu Province

正Recently,Chinalco and Gansu Provincial People’s Government signed"Framework Agreement for Strategic Cooperation on Reform,Restructuring and Transition Development of Chinalco’s Electrolytic Aluminum Enterprises in Gansu",signifying that the strategic cooperation between Chinalco and Gansu Province had made new substantive progress.     

Unavoidable Economic Cycle:30% Of Nonferrous Metal Companies Were Involved In Restructuring

正Owing to continual downturn in real estate and bulk commodity markets,a number of traditional industries in China suffered unfavorable impact in performance.With the progressive disclosure of third quarter report,the no-pleasant-surprise performance of     

Baotou Rare Earth Became the World's Biggest High Performance Magnetic Material Base

正The High Performance Magnetic Material Phase II Project,an industry upgrading project implemented by Inner Mongolia Baotou IronSteel Rare Earth(Group)Hi-tech Co.,Ltd,recently basically finished equipment commissioning,signifying that the enterprise had developed the production capacity of15000 t/a Nd-Fe-B strip casting alloy and 5000t/a Nd-Fe-B magnet,thus becoming the world’s     

Introducing Two Central Enterprises to Integrate Rare Earth Industry,Shandong Rare Earth Group Breaks Surface

正With the signing of"Letter of intention for Propelling Integration of Shandong Rare Earth Enterprises"between Shandong Province Commission Of Economy and Informatization,China IronSteel Research Institute Group("China Steel Institute"),and China Rare MetalsRare Earth Co.,Ltd("China Rare Earth"),the"Shandong Rare Earth Group"jointly set up by the 3 units thus broke surface.On August 9,reporters of the China Economic Herald learned from Shandong Province     

Aluminium Production by Province or City in 2014

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