TiC_p/Fe复合材料铸造性能的研究

对TiCp/Fe复合材料的体收缩率、线收缩率和流动性进行了测定,并与普通碳钢、灰铸铁进行比较。结果表明:TiC增强颗粒使TiCp/Fe复合材料的体收缩率较小,体收缩性能高;而流动性则遵循随w(C)量增加而增加的规律;TiCp/Fe复合材料的凝固过程还倾向于集中缩孔,有利于补缩。     

固态收缩与铸造残余内应力关系的研究

研究了铸线收缩率总量和弹性线收缩率与灰铸铁铸造残应应力的关系，提出了弹性线收缩率的概念及其确定方法。     

Al3Ti/ZL101原位复合材料的铸造性能研究

测试了Al3Ti/ZL101原位复合材料的流动性、线收缩率、热裂倾向及铸造应力，分析了影响铸造性能的各种因素。结果表明：Al3Ti/ZL101原位复合材料的热裂抗力较基体材料大、线收缩率较基体材料小、铸造应力略大于基体材料；在780℃以下，Al3Ti/ZL101原位复合材料的流动性优于基体材料。对Al3Ti/ZL101原位复合材料采用同基体材料相同的铸造工艺即能满足生产要求。     

含17%～20%Mn高锰钢风扇磨煤机打击板的耐磨性

含１７％～２０％Ｍｎ高锰钢在高速运动煤块的冲蚀磨损条件下,较一般高锰钢、合金化高锰钢有更好的加工硬化能力,并有足够的韧性。用该高锰钢制成的火力发电厂用大型风扇磨煤机打击板的使用寿命较普通ＺＧＭｎ１３高锰钢打击板寿命提高两倍。     

ZGMn13钢铲斗齿强韧化处理

ＺＧＭｎ１３钢铲斗齿强韧化处理南昌湾里工具厂（３３０００４）王荣滨粤矿机厂海燕按标准成分和常规水韧处理工艺（图１）生产的ＺＧＭｎ１３钢铲斗齿，早期磨损和断齿为其主要失效形式。为此，我们在标准ＺＧＭｎ１３钢基础上加入０．５％～０．６％Ｍ。和改进水韧处理...     

Fe—Mn—Al合金的腐蚀性能与钝化膜的研究

应用阳极极化及ＡＥＳ／ＸＰＳ技术，研究了Ｆｅ－３０．８Ｍｎ－８．２Ａｌ奥氏体合金在ｐＨ值为－０．８至１５．３的水溶液中的腐蚀性能，并与Ｆｅ－３０Ｍｎ合金，低碳钢，９％Ｎｉ低温钢及１Ｃｒ１３不锈钢进行对比。在所测试的水溶液中，该合金的腐蚀抗力优于低碳钢的Ｆｅ－３０Ｍｎ合金，与９％Ｎｉ钢相当，但不及１Ｃｒ１３不锈钢。     

高锰钢和U71Mn钢在加焊接介质焊接时的接头组织

用一种焊接介质,采用等离子弧堆焊结合闪光对焊的方法将ＺＧＭｎ１３钢和Ｕ７１Ｍｎ钢加焊接介质进行焊接。结果发现ＺＧＭｎ１３钢热影响区内无碳化物析出,Ｕ７１Ｍｎ钢热影响区内无马氏体产生。中间介质为单相奥氏体组织,熔合区存在大约１０％的δ铁素体     

稀土镁对铸态高锰钢机械性能的影响

实验了稀土镁对铸态高锰钢机械性能的影响．结果表明，在一定的Ｃ、Ｍｎ、Ｓｉ成分中，加入ＲＥＭｇ合金均使其铸态机械性能有所提高．同时在工业设备上试验证实，加入ＲＥＭｇ的某种成分之高锰钢，在铸态时其耐磨性能、机械性能均已达ＺＧＭｎ１３－１和ＺＧＭｎ１３－２（ＧＢ５６８０－８５）水平并超过了铸态使用的７５Ｍｎ１３     

高锰钢在U71Mn钢在加焊接介质焊接时的接头组织

用一种焊接介质,采用等离子弧堆焊结合闪光地焊的方法将ＺＧＭｎ１３钢和Ｕ７１Ｍｎ钢加焊接介质进行焊接。结果发现ＺＧＭｎ１３钢热影响区内无碳化物析出,Ｕ７１Ｍｎ钢热影响区内无马氏体产生。中间介质为单相奥氏体组织,熔合区存在大约１０％的δ铁素体     

国外动态

国外动态汽车用新型非磁性高Ｍｎ钢板韩国浦项钢铁公司开发了汽车用非磁性高Ｍｎ钢钢板，其强度为传统汽车用冷轧钢板的３倍，并具有良好的成形性。新型材料的化学成分（％）：Ｃ０．５５，Ｓｉ０．１３，Ｍｎ２．５，Ｐ０．００８，Ｓ０．００１，Ａ１１．５，Ｎ０．０１...     

厚大灰铸铁冷却壁的铸造工艺

针对厚大灰铸铁冷却壁在铸造过程中易出现收缩等缺陷问题,从铸型条件、铁液质量及铸造工艺等三方面采取相应措施解决了冷却壁铸件外弧面缩凹及管口尺寸偏差较大等问题。     

Effect of cooling rate on solidification structure and linear contraction of a duplex stainless steel

Cooling rate is a key factor that can drastically affect the phase transformation and thermal stress of duplex stainless steels. Therefore, in this research, different sand moulds were used to explore the influence of cooling rate on the solidification of the 2304 duplex stainless steel (DSS). The macro and micro structures of the 2304 DSS were investigated. Small equiaxed grains are obtained in chromite sand mould sample with a lower pouring temperature and a higher cooling rate, whereas coarse columnar and equiaxed grains are found in silica sand and refractory powder mould samples. The size of austenite phase is significantly increased with decreasing cooling rate, while the ferrite phase content ranging from 51.6% to 53.9% does not change obviously. In addition, the linear contraction of the 2304 DSS decreases from 2.34% to 1.09% when the mean cooling rate above 1,173 K increases from 0.99 K·s-1 to 3.66 K·s-1.     

应用塑件的工艺限制收缩特性获得塑件高精密孔的工艺方法

塑件外形的尺寸和形位精度可以通过精密注射模的精确导向、定位及二次定位加以解决,而塑件内形的尺寸和形位精度,要获得标准公差数值为IT6～7级,圆柱度小于0.01mm精度的要求,看起来是乎是不现实的事情。通过应用塑料的成型二次工艺限制收缩特性解决了这一塑件成型的难题,并成功地使塑件的内孔获得IT6精度,孔的不圆柱度可小于0.002mm的水平,并且加工的方法极其简单。     

Casting a Small-diameter Tin Wire by the OCC (Ohno Continuous Casting) Process

Abstract

Tin wires of 2 mm dia have been cast by the horizontal OCC process at speeds between 0.02 m/min and 4.2 m/min. It was found that unlike the casting of larger diameter rods, it was possible to continue casting, even if the solid-liquid interface existed outside the mould. If the mould exit temperature and the mould-cooler distance were maintained at 267°C and 2 mm respectively, the solid-liquid interface was located at the mould exit when the casting speed was 0.35 m/mln. However, when the casting speed exceeded about 1.2 m/min, the cast surface of the wire deteriorated and exhibited a matted appearance due to the formation of ridges. With a casting speed of 4.2 m/min, the solid-liquid interface location was estimated to be about 4 mm outside the mould. A calculated temperature distribution within the solidifying strand revealed that the solid-liquid interface entered the cooling water when the casting speed was 1.2 m/min. Thus, in order to obtain a cast wire with a high surface finish, the strand should be solidified outside the cooling water. Casting parameter values corresponding to the condition where the solid-liquid interface reaches the mould exit were considered to be critical co-ordinates for runout (breakout). When the solid-liquid interface is located between the mould and the cooling water, tight control of the casting process, and in particular control of the metal head, is essential in order to avoid dimensional instability and runout of the liquid metal.     

铬对含硼高锰钢铸造性能的影响

利用螺旋试样和ZQS-2000型双试棒合金热裂线收缩仪分别测定了不同铬含量(0%～3.0%)含硼高锰钢的流动性和线收缩率。结果表明,随着铬含量的增加,试样的流动性显著降低,对线收缩的影响不大。试样的流动性长度由483mm变为228mm,其长度值降低52.8%;线收缩率在2.510%～2.269%之间变化,下降了0.24%。含硼高锰钢的一次结晶组织,随着铬含量的增高,枝晶间距增大,晶粒变大。     

ZL105合金悬浮铸造工艺研究

对ZL105合金悬浮剂的制备、加入量、加入方式、加入温度及熔化时间等悬浮铸造工艺进行了初步探讨。结果表明,ZL105合金采用恳浮铸造简单易行,而且对减小体收缩、细化晶粒组织、降低壁厚对晶粒组织的敏感性以及提高针孔度级别有明显效果。     

微机化合金线收缩仪的研制

本文介绍了一种新型的合金线收缩仪。该系统以单片机8031为核心,采用自主开发的传感器测定位移量,能够对合金温度及对应的线收缩率进行同步测量和显示。该仪器具有体积小、测量精度高、性能稳定、抗干扰能力强、操作方便等优点。     

Discussion on "proportional solidification technology" for nodular iron casting method

H ow should the graphitization expansion be reasonably utilized to feed nodular iron castings? H ow should the consideration be given to both feeding from feeders and self-feeding by expansion? These two problem s are the hot spotsofdiscussion on feeding m ethod ofnodulariron castings at present. In this regard, reference [1] published som e viewpointswhich cause differentcom m ents.W ith the wish to prom ote the discussion on shrinkage problem sofnodulariron castings and based on his investig…     

粉末涂装过程中表面缩孔缺陷分析及对策

本文论述了粉末涂装过程中的表面缩孔,包括气孔、针孔、水孔等产生的原因、解决办法及预防措施,指出基材的表面状态、前处理、烘干、固化、粉末涂料、压缩空气及管理等都与表面缩孔有关。针对不同的缩孔,应采取不同的解决办法和预防措施。