半钢轧辊试制工艺探讨

文章主要介绍根据半钢轧辊的成分特性 ,采用顶注工艺并参照大连钢厂的热处理工艺 ,制定适合本公司实际的热处理工艺 ,使半钢轧辊的试制既缩短了时间 ,又保证了质量 ,机械性能符合 GB1 50 3- 89标准要求的经验     

弹簧钢30W4Cr2VA钢的工艺研究与试制

对弹簧钢30W4Cr2VA的加热退火制度进行改进将原来的钢锭退火、冷却装炉改为热送加热轧制。取得了较好效果。     

40MnB钢生产试制

采用90 t电炉-90 t LF+VD-连铸-连轧工艺生产40MnB钢,其化学成分、低倍组织、力学性能均满足技术标准要求,可进行批量生产。     

齿轮用钢15CrNi6的试制

介绍15CrNi6齿轮钢的技术要点、材质特点、试制工艺及产品质量水平。     

M2高速钢盘条退火工艺的优化

采用不同等温退火工艺对M2高速钢盘条进行了退火处理,研究了加热温度、保温时间和等温转变时间等工艺参数对其显微组织和力学性能的影响,在此基础上优化了其等温退火工艺。结果表明:加热温度过高和保温时间过长会使一次碳化物颗粒长大粗化,降低盘条的塑性;而等温转变时间过短不利于珠光体的形成,同样使盘条塑性不高;M2高速钢盘条比较合理的退火工艺为880℃加热2 h,炉冷至760℃等温5 h,可得到退火索氏体中弥散分布着细小球状一次碳化物颗粒的组织,使高速钢盘条具有良好的塑性。     

60Si2Mn钢亚温淬火工艺研究

采用正交回归处理的方法,研究淬火温度、回火温度对60Si2Mn钢强韧性的影响,并分析了该钢亚温淬火后的组织和力学性能。结果表明,60Si2Mn钢在800℃淬火时,综合力学性能达到最佳。     

从一种压力容器的试制谈发展精品工艺

发展精品工艺,提高企业的核心竞争力,这是我国加入WTO以来,从事机械制造行业的企业的迫切需要。但如何去发展精品工艺,这是一个值得注意的问题。我厂依靠工艺人员和工人技师成功地试制出高难度压力容器,就是一个典型的事例。 1.压力容器试制的概况 我厂从事液化气钢瓶、贮气罐等压力容器已有多年的历史了,热加工和冷加工能力都比较强。所以当我厂得知有一种压力容器好儿个单位都造不出后,就立即派人去承     

60CrMnMo钢淬火开裂分析及解决措施

我厂生产的各种规格的多工位自动锻压机，其凹模座后的垫板是主要受力件之一，设计要求的材质是60CrMnMo，为一种热轧辊钢，通常在较低的硬度下使用。在实际生产过程中，垫板曾多次发生开裂，给工厂造成了很大损失，并影响了往产周期。本文仅就在热处理过程中开裂及热处理工艺参数进行分析，探讨避免开裂的工艺措施，通过建立     

Atom probe tomography characterization of heavily cold drawn pearlitic steel wire

Atom Probe Tomography (APT) was used to analyze the carbon distribution in a heavily cold drawn pearlitic steel wire with a true strain of 6.02. The carbon concentrations in cementite and ferrite were separately measured by a sub-volume method and compared with the literature data. It is found that the carbon concentration in ferrite saturates with strain. The carbon concentration in cementite decreases with the lamellar thickness, while the carbon atoms segregate at dislocations or cell/grain boundaries in ferrite. The mechanism of cementite decomposition is discussed in terms of the evolution of dislocation structure during severe plastic deformation.     

9%Ni钢用国产镍基焊丝的焊接试验研究

针对镍基焊丝的热裂纹敏感性试验,研制出FISCO热裂纹试验装置,利用该装置对研制的ERNiCrMo-3镍基焊丝进行焊接热裂纹敏感性试验,结果表明,研制焊丝的热裂纹敏感性与进口焊丝相当,均具有较低的热裂纹敏感性。采用研制焊丝焊接9%Ni钢的工艺试验结果表明,焊接接头各项力学性能优良,焊缝组织为纯奥氏体组织,析出相很少,可以满足大型LNG储罐的设计要求。     

X70管线钢冷丝填充埋弧焊焊接工艺

根据X70管线钢的焊接性,提出了采用冷丝埋弧焊的工艺方法来解决焊接接头热影响区的脆化现象,通过向熔池中添加＂冷丝＂,消耗过热能量来提高焊接接头的韧性。确定X70管线钢在不同线能量下的最佳冷丝填充速度;最终得出X70管线钢冷丝埋弧焊焊接工艺参数。     

Ultrastructural effect of self-ligating bracket materials on stainless steel and superelastic NiTi wire surfaces

Frictional interactions between wires and brackets reduce the efficacy in orthodontic treatments. Self‐ligating brackets (SLBs) are now more often used due to lower frictional forces when compared with conventional‐ligating brackets. In this study, scanning electron microscopy and atomic force microscopy were used to examine the microstructural effects of stainless steel and ceramic SLBs on the surface roughness of stainless steel and superelastic NiTi wires both after in vivo clinical orthodontic treatment as well as in in vitro three‐point bending experiments. A combination of two wires—0.019 in. × 0.025 in. stainless steel wires and 0.016 in. superelastic NiTi wires—and two SLBs—both passive‐type stainless steel SLBs and active‐type ceramic SLBs—was applied for 4 months (bicuspid‐extraction) in an in vivo setting and for 1 month in an in vitro setting (200 g loads). After the SLB treatments, all wires exhibited severe scratches secondary to frictional interactions with the brackets. When used with the stainless steel SLBs (Damon 3MX®), the surfaces of 0.019 in. × 0.025 in. stainless steel (P < 0.0001) and 0.016 in. superelastic NiTi wires (P < 0.05) were significantly smoother than when used with the ceramic SLBs (Clippy‐C®). Such results suggest that orthodontic treatments with stainless steel SLBs are more effective than with ceramic SLBs. Microsc. Res. Tech. 75:1076–1083, 2012. © 2012 Wiley Periodicals, Inc.     

电镀金刚石线锯的制造工艺研究

利用复合电镀法,以直径φ0．3mm的琴钢丝为基体,选取400。的金刚石作为磨料,选用瓦特型镀液,采用埋砂法制造金刚石线锯。利用显微镜测试了镀层厚度,利用体视显微镜观察了线锯形貌。结果表明,上砂电流密度在2．0A／dm2,上砂时间20min时能够获得金刚石磨粒分布均匀、与基体结合力好的金刚石线锯;给出了本实验条件下制造电镀金刚石线锯的最佳电镀工艺参数。     

用数字图像处理技术检测钢丝绳表面缺陷

介绍一种基于纹理特征提取的数字图像处理技术进行钢丝绳检测的新方法。首先利用图像处理的方法对在役钢丝绳图像进行预处理,以减小或消除噪声的影响,然后提取图像的纹理特征值——熵和平滑度,通过线性分类器来判断在役钢丝绳表面是否有断丝或锈蚀等缺陷。实验结果证明,该检测方法在实际应用中能代替人工目测,使用方便,能够满足实时要求。     

S型截面不锈钢钢丝成形工艺和模具设计

根据不锈钢材料强度高、硬化严重和S型横截面形状复杂、尺寸小的特点,确定采用两道次辊弯预成形、两道次辊模拉拔、一道次固模精拉的工艺方案,设计S型截面不锈钢钢丝五个道次成形工艺过程的轧辊孔型。此项研究成果对S型截面钢丝有重要的参考价值。     

Investigation into erosion rate of AISI 4340 steel during wire electrical discharge turning process

Wire electrical discharge turning (WEDT) process was developed to generate cylindrical form on any electrically conductive material applied in aerospace and automotive industry. The mechanism of metal removal in WEDT process is by means of successive spark discharge. Each spark results in the formation of crater. In the present work, a new model is proposed to predict the erosion rate of each spark for a given discharge energy. A new method is proposed to measure the crater depth from 2D roughness profile of the machined component. The proposed model is validated by conducting experiments on AISI 4340 steel and the results obtained are presented in the paper. It is observed that the results are in close proximity with the experimental values at low discharge energy. The stochastic erosion mechanism of WEDT process is analyzed using scanning electron microscope images of spark eroded wire. Using the proposed model the erosion rate can be controlled and better surface characteristic of machined surface can be achieved.     

影响钢丝绳疲劳断裂的因素及提高疲劳寿命的技术措施

讨论了影响航空钢丝绳疲劳断裂的因素,通过试验研究热处理过程中钢丝完全索氏体化和不完全索氏体化时对钢丝绳的疲劳寿命影响,研究了拉拔时总压缩率、部分压缩率对钢丝绳的疲劳寿命影响,找出了能够提高疲劳寿命的技术措施。     

基于遗传算法的拉丝机压缩比的优化设计

以LZ-9/1200拉丝机为例,运用遗传算法,以总拉拔力最小为目标,对多道次钢丝拉拔成形过程的每道次部分压缩比进行了优化设计。以Java软件为编程工具,采用面向对象的编程技术,经过选择、交叉、变异多次迭代,得到了符合要求的满意解,为实际生产提供了可行方案。