耐磨铸铁筛板的研究和应用

分析了热矿筛筛板使用寿命短的原因，反材料的高温硬度低和高温耐磨性差是主要因素。为了改善筛板材质的性能，对其化学成分进行了科学设计，并探讨了铸造和热处理工艺。研究表明，新筛板的使用寿命达到CrMnN钢筛板的两倍。新筛板价格与CrMnN钢的相近，经济效益显著。     

热烧结矿筛分机耐磨筛板的研制和应用

首先分析了热烧结矿筛分机 (简称热矿筛 )筛板使用寿命短的主要原因是由于筛板材质高温硬度低、高温耐磨性差。为了提高热矿筛的工作效率 ,提出了改进热矿筛筛板材质的必要性 ,并对新筛板材质的化学成分进行了科学设计 ,同时对新筛板的铸造及热处理工艺进行了探讨。研究结果表明 ,新研制的筛板使用安全、可靠 ,使用寿命达到CrMnN筛板的两倍 ,价格与CrMnN筛板相当 ,若在全国推广这种筛板 ,将会产生显著的经济效益。     

新材质热矿筛筛板的研究

本文改进了原热矿筛筛板材质CrMnN耐热钢成分,设计了一种高铬铁材料,对所设计材料及原筛板2Cr20Ni6材料进行金相分析,在最终热处理后,做高温性能实验比较,结果表明,所设计成分的高铬铁是应用于热矿筛筛板工况的较理想材料.     

热矿振动筛新型筛板的研制及应用

通过改进热矿振动筛的筛板结构，选择合适的筛板成及改进铸造工艺，有效地提高了筛板的结构强度，刚性和铸造精度，改善了它的耐磨、耐热和抗急冷，急热性能，并消除了筛板的铸造缺陷，从而提高了筛板的使用寿命。     

矿用聚氨酯筛板研制成功

由冶金部马鞍山矿山研究院与南京橡胶厂、首钢大石河铁矿合作研制的细孔聚氨酯筛板及由山西省化工研究所研制的大孔聚氨酯筛板,最近分别通过了冶金部和山西省组织的鉴定。马鞍山矿山研究院等单位研制的聚氨酯筛板由南京橡胶厂加工,用于ZKB1856A型双轴直线振动筛,取代不锈钢筛筛板。筛孔的尺寸(宽×长)为1.8×16.25mm,筛孔有效面积为21.6％,筛板设计采用组合式,拼装结构,插入式安装。经1990年在首钢大石河铁矿进行工业试验表明,该筛板受铁矿石冲击部位的纯使用寿命达64天,而同样条件下使用的不锈钢筛板的寿命仅为21天。使用聚氨酯筛板降低了钢耗,提高了筛分机的作业率,经济效益显     

KmTBCr15RE导卫板的研制

新钢公司线材厂轧机原使用的高铬铸铁Ｃｒ２９Ｎｉ导卫板寿命低，现研制成新材质ＫｍＴＢＣｒ１５ＲＥ导卫板，经测试及试用表明，新材质导卫板与原材质导卫板相比，降低了生产成本，延长了使用寿命，提高了轧机生产效率。     

溢流型球磨机出料端圆筒筛改进优化

近年来，随着德兴铜矿开采矿石硬度的逐步增加， ?5.5 m×8.5 m溢流型球磨机循环负荷明显增加，造成球磨机圆筒筛筛分效率不高，排粗颗粒大量增加。针对这一问题，通过对圆筒筛导流板结构、圆筒筛筛孔尺寸进行分析，并采用ROCKY仿真模拟技术进行仿真模拟，然后将原有圆筒筛挡环状导流板改为双螺旋+叠状分布，将筛板改为橡胶材质，将筛孔尺寸由20 mm×40 mm减小至16 mm×40 mm。圆筒筛改进优化后，排粗中-2 mm粒级较改进前下降了54.46%，圆筒筛排粗量较同类型球磨机减少了约85%，溢流、排矿中-0.075 mm含量、旋流器分级量效率及返砂比均在正常范围内，并且不影响球磨机的正常运行，取得了较好的效果。     

TZS型矿用振动筛在301号炉的使用

1旧式振动筛的弊端长期以来，我厂炉槽下返矿量过多，有时返矿率高达20％（表1），严重影响生产成本，此事早就引起厂领导和有关单位的高度重视。1990年4月份厂审计处对此进行了审计调查，但问题并没有彻底解决。表11990年1～4月份301号炉返矿且据分析，返矿过多的原因有：（1）301号炉槽下共振筛筛板倾角偏小，只有5”，造成振动时间长，产生部分粉末。（2）槽下共振筛工作环境恶劣，灰尘多，不便于检查，下料过快，合格矿从筛子两侧溢出。（3）筛板损坏或错位、弹簧断裂未及时发现和检修，筛板不规格，筛板间有空隙和死角。为此一铁厂曾搞…     

提高辊轴筛筛征使用寿命的探索

对辊轴筛筛片使用工况条件、现有材质及热处理工艺进行分析，批出了筛片使用寿命短的原因。采用新的热处理工艺后，筛片齿部硬度明显提高并稳定均匀，使用寿命稳定且有所提高。     

南钢炼铁新厂大小振动筛的改造

大振动筛筛板使用寿命短是焦化行业的普遍现象,其筛体上部焦炭直接冲刷处筛板使用寿命只有2-3月.对此采取增加一层耐磨合金板的改造措施,提高了筛板使用寿命.南钢新炼铁厂小振动筛原为悬绕网式,噪音大、悬绕轴易磨损断裂,造成堵孔,筛分效果差,生产效率低.经过多次改造,成功地解决了上述问题.     

Bridge Deck Construction Using Type K Cement

Because drying shrinkage cracking is a major source of bridge deck cracking, and because shrinkage compensating concrete (SCC) is known to substantially reduce shrinkage cracking, the use of SCC should be closely examined in an effort to increase the durability and service life of bridge decks. One of the concerns regarding the use of SCC is its more demanding construction requirements for placement time and for curing. This paper addresses relevant material and construction issues that have resulted in the successful use of SCC for bridge decks. The Ohio Turnpike Commission (OTC) has used SCC exclusively for its new and replacement bridge decks for the past 12 years, and they have been very satisfied with its performance to date. The OTC's evaluation of SCC is that it greatly mitigates shrinkage cracking. The OTC's requirements for SCC at the concrete plant, in-transit, and at the job site are included in this paper. The OTC's construction procedures are presented in the form of a chronological sequence of photographs illustrating the construction activities on a new SCC deck placement in 1994.     

Performance of Coated Reinforcing Bars in Cracked Bridge Decks

The presence of cracks in bridge decks that are reinforced with epoxy-coated reinforcing (ECR) bars has raised some concerns among bridge and maintenance engineers in the state of Iowa. To study the effects of deck cracking on the performance of ECR bars, several concrete cores that contained reinforcing bars were collected from 80 bridges that are located in different counties throughout the state of Iowa. These samples were collected from cracked and uncracked areas of the bridge decks. Concrete powder samples were collected from these cores and were analyzed in the laboratory to determine the diffusion of the chloride in the bridge decks. This study revealed that no sign of corrosion was detected for the ECR rebars that were taken at the uncracked bridge deck locations. In addition, no delamination or spalling was observed for the bridge decks where bars in the core samples, which were taken at the cracked bridge deck locations, exhibited signs of corrosion. The collected ECR rebars samples were rated according to the degree of the corrosion that was observed on each bar. These ratings were used to develop condition/age relationships that were utilized to estimate the functional service life of bridge decks that are reinforced with ECR bars.     

Realistic Assessment for Safety and Service Life of Reinforced Concrete Decks in Girder Bridges

The lack of safety of deck slabs in bridges generally causes frequent repair and strengthening. The repair induces great loss of economy, not only due to direct cost by repair, but also due to stopping the public use of such structures during repair. The major reason for this frequent repair is mainly due to the lack of a realistic and accurate assessment system for bridge decks. The purpose of the present paper is therefore to develop a realistic assessment system which can estimate reasonably the safety, as well as the service life of concrete bridge decks, based on the deterioration models that are derived from both the traffic loads and environmental effect. A deterioration model due to chloride ingress is first established. The damage models due to repetitive traffic loads considering the dry and wet conditions of deck slabs are proposed. These models are used to calculate the remaining life of a bridge deck slab. A prediction method for service life of deck slab due to loading and environmental effects is developed based on material, as well as structural evaluation. The proposed method includes the assessment of corrosion in material level, and the analyses of flexure, shear, and fatigue in structural level. Finally, an assessment system for prediction of safety and remaining service life is developed based on the theories established in this study. The developed assessment system will allow the correct diagnosis of damage state and the realistic prediction of service life of concrete decks in girder bridges.     

Performance Comparison of Four Fiber-Reinforced Polymer Deck Panels

In an effort to assess the constructability and performance of bridges with fiber-reinforced polymer (FRP) composite decks, the short-term and long-term responses of a 207 m, five-span bridge retrofitted with four different FRP panel systems were monitored. The overall aspects of the panel systems, connection details, and construction techniques are presented prior to presentation of the observed and measured responses. Key design parameters (impact factors, girder distribution factors, and level of composite action) for FRP and reinforced concrete decks are evaluated. This paper demonstrates that FRP replacement decks are a viable alternative to reinforced concrete decks and identifies the differences in performances of various FRP deck systems. Two of the FRP panel systems were found to perform considerably better than the other deck systems. Issues that may reduce the service life of FRP deck systems are presented and discussed.     

提高振动筛轴承润滑质量延长轴承工作寿命

针对烧结矿生产线中的振动筛轴承使用寿命过短的现象,通过对润滑脂的粘度、极压性和使用温度以及轴承温度监测记录的分析,找到一种大幅延长轴承寿命的方法。     

Designing and Testing of Concrete Bridge Decks Reinforced with Glass FRP Bars

In addition to their high strength and light weight, fiber-reinforced polymer (FRP) composite reinforcing bars offer corrosion resistance, making them a promising alternative to traditional steel reinforcing bars in concrete bridge decks. FRP reinforcement has been used in several bridge decks recently constructed in North America. The Morristown Bridge, which is located in Vermont, United States, is a single span steel girder bridge with integral abutments spanning 43.90 m. The deck is a 230 mm thick concrete continuous slab over girders spaced at 2.36 m. The entire concrete deck slab was reinforced with glass FRP (GFRP) bars in two identical layers at the top and the bottom. The bridge is well instrumented at critical locations for internal temperature and strain data collection with fiber-optic sensors. The bridge was tested for service performance using standard truck loads. The construction procedure and field test results under actual service conditions revealed that GFRP rebar provides very good and promising performance.     

高温过热器12Cr2MoWVTib（102）钢管的显微组织和相结构分析

本文对原始状态和在火力发电厂使用不同时间的高这热器１０２钢管进行了显微组织和相结构变化规律的探讨和研究。显微组织研究表明，１０２钢管在高温高压下长期运行过程中，使用温度对显微组织和碳化物相有明显影响，而使用时间对其影响不如温度影响强烈。碳化物颗粒图象分析表明，碳化物随着使用时间缓慢长大，而新的碳化物不沉淀，使颗粒总数不断增加，颗粒，间距逐渐缩小。Ｘ射线衍射数据证明，钢管在高温长期使用过程中，ＭＣ相     

回转窑内衬新工艺的应用

回转窑作为高温煅烧物料的主要设备,被广泛应用在铝用阳极石油焦的煅烧工序中,而作为保护回转窑金属筒体及减少窑内热量损失的回转窑内衬的使用寿命,直接影响到回转窑设备的正常使用寿命.本文重点从新型预制块的使用及预制块与现场浇注相结合的新工艺的应用,对回转窑内衬使用寿命的延长及施工工艺的改进来进行论述.