钻杆接头材料激光相变硬化层的组织和硬度研究

采用功率为 2kW、扫描速度为 10 0mm/min的工艺参数对钻杆接头材料 30CrMnSiA钢进行了表面相变硬化处理 ,研究了相变层的组织和硬度特征。实验结果表明 ,30CrMnSiA钢表面相变硬化层分为完全淬硬层、过渡层和受热影响的基体组织 ,硬化层的显微组织明显细化 ,其表面层的硬度比高频淬火的硬度提高了 30 % ,淬硬层深度达 1 7mm ,比高频淬火深度提高近 1倍。     

硼氮共渗提高5CrMnMo钢热锻模使用寿命的研究

通过对 5CrMnMo钢试样进行硼氮共渗热处理工艺试验研究 ,确定了提高 5CrMnMo钢制热锻模使用寿命的硼氮共渗处理工艺 ,并与渗硼层相比较 ,结果表明 ,其共渗层具有更优良的耐磨性和耐高温氧化性。与等温处理相比 ,共渗后经等温处理的热锻模使用寿命可提高 2倍以上     

渗硼对Q235钢耐铝液腐蚀性能的影响

研究渗硼对钢耐铝液的腐蚀性能的影响,通过固体渗硼的方法在Q235表面获得渗硼层,并在750℃对未渗硼试样和渗硼试样在纯铝液中分别腐蚀1、2、3、4和5 h,测量试样的腐蚀失重、观察界面的腐蚀形貌并测定其物相,分析并研究渗硼层耐铝液腐蚀的机理。研究发现,渗硼层组织与基体结合紧密,750℃腐蚀5 h后,仍有渗硼层存在,对基体有良好的保护作用。渗硼层隔绝了铝液接触铁基体,减缓Fe_2Al_5的生长,降低剥落腐蚀概率,减缓铁基体溶解腐蚀速率,提高基体的耐铝液腐蚀性能。     

提高凿岩机钎尾寿命的热处理工艺研究

主要分析了目前铬镍钢钎尾存在的问题和主要失效原因,从选材和热处理工艺优化两方面首手寻找提高钎尾寿命的途径。在热处理工艺上首先控制渗层质量,再从后续热处理中对不同温度等温淬火工艺、淬回火工艺进行对比,结合试验台疲劳试验和矿山寿命实验分析,得到CN共渗后低温等淬火、回火处理是该钢种较为理想的热处理工艺。     

渗硼对Q235钢耐铝液腐蚀性能影响研究

为研究渗硼对钢耐铝液的腐蚀性能的影响,通过固体渗硼的方法在Q235表面获得渗硼层,并在750℃对未渗硼试样和渗硼试样在纯铝液中分别腐蚀1h、2h、3h、4h和5h,测量试样的腐蚀失重、观察界面的腐蚀形貌并测定其物相,分析并研究渗硼层耐铝液腐蚀的机理。研究发现：渗硼层组织与基体结合紧密,750℃腐蚀5小时后,仍有渗硼层存在,对基体有良好的保护作用。渗硼层隔绝了Al液接触Fe基体,减缓Fe₂Al₅的生长,降低剥落腐蚀概率,减缓Fe基溶解腐蚀速率,提高基体的耐铝液腐蚀性能。     

40Cr钢硼稀土共渗的组织与性能研究

本文对４０Ｃｒ钢进行了硼稀土共渗处理，得到了稀土硼的共渗层。研究了稀土元素对渗层组织结构、硬度、耐磨性以及渗层冲击局性和表面耐蚀性的影响。结果表明：稀土元素Ｌａ和Ｃｅ渗入了钢中，改善了渗层的组织，使渗层的表面硬度和耐蚀性及耐磨性均有明显提高。尤其是渗层的局性显著地增大。脆断前吸收的功增大了一倍。     

40Cr钢的磨削淬硬层与磨削参数的关系

针对矿山机械常用材料之一40Cr钢应用了磨削淬火技术, 并在试验中改变磨削用量以研究材料的淬硬层情况。试验后对试件进行金相组织观测, 发现可得到一定厚度的马氏体; 进行硬度值测量发现: 在变进给情况下, 强化层厚度为1.2～1.4 mm, 硬度值平均为HV760(HRC62), 淬硬厚度随着进给速度减少而增加; 在变切深情况下, 强化层厚度为0.8～1.6 mm, 硬度值平均为HV700(HRC60), 淬硬厚度随着切深的增加先增大后减少。两种手段得到的淬硬层硬度均远远高于基体硬度值HV255(HRC23), 证明了该种新技术经济实用, 效果良好, 并且宜采用缓进给的方式进行。     

双层辉光离子渗Cr合金层组织和性能

在Q235钢表面进行双层辉光离子渗Cr，表面Cr含量约为40％，渗层厚度近50 μm.然后进行超饱和渗C，表面含C量达到2.7％左右，超过平衡碳计算值.随后进行淬火＋低温回火处理，经X射线衍射分析，合金化层碳化物类型为M23C6，M7C3，尺寸为1～2 μm.表面硬度达到HV 1 200左右.将表面冶金试样进行摩擦因数和耐磨性能试验，结果表明，表面冶金试样摩擦因数为0.21～0.28，耐磨性是Q235钢渗碳淬火试样的1.62倍.将表面冶金试样在10％的H2SO4、3.5％的NaCl水溶液和H2S富液（含H2S 5～8 g/L，NH3·H2O 20 g/L）中进行电化学腐蚀试验，结果表明，表面冶金试样在10％的H₂SO₄、3.5％的NaC1水溶液和H2S富液中的耐腐蚀程度比Q235基体试样分别提高了2.35，3.10，2.14倍.     

煤矸石渗剂渗硅层耐磨性研究

为提高材料表面的耐磨性,利用固体粉末法,以煤矸石为主渗剂,铝粉和镁粉为还原剂,在Q235钢表面制备渗硅层。煤矸石渗硅层中有Fe3Si、Al2Si Fe等新相生成;渗硅层主要由含Si的α固溶体组成,厚度可达100μm;渗硅层硬度达348.7 HV0.1,基体为134.5 HV0.1;磨粒磨损性能测试结果表明,渗硅层在0#、01#和02#金相砂纸下耐磨性较基体分别提高2.79倍、2.37倍和2.03倍;在20 N、40 N和70 N的附加载荷下耐磨性分别提高2.03倍、2.18倍和2.82倍;渗硅层在低速(60 r/min)和高速(120 r/min)下耐磨性分别提高2.02倍和2.53倍。煤矸石渗硅具有可行性,能够提高低碳钢表面综合性能。     

QPQ盐浴氮化对合金灰铸铁显微组织和耐磨性的影响

通过X射线衍射相分析和金相分析,发现采用不同的加热、保温和冷却方式获得的不同基体组织的合金灰铸铁,经QPQ盐浴氮化处理后渗层组织中存在Fe3O4和Fe2N;铁素体含量越高,渗层越厚。通过对不同基体组织的合金灰铸铁在QPQ处理前后的磨损速率的比较,发现经QPQ处理后的合金灰铸铁试样磨损速率为QPQ处理前的1.6%～5.7%。     

灰口铸铁渗硼的研究

通过箱式渗硼法利用固体渗硼对灰口铸铁进行了渗硼处理,采用配置好的渗硼剂,在850℃,900℃和950℃下分别实施了时长为2h,3h,4h,5h和6h的渗硼处理。实验得出了灰口铸铁硼化层厚度、显微硬度及渗硼样品的显微组织。     

Wärmebehandlungsprozesse für die Windkrafttechnik

For building a wind energy plant a variety of thermal and thermochemical treated parts are required. The big dimensions of most of the parts in combination with high requirements on reliability and consistency of the heat treatment results show the need for optimised heat treatment solutions. The variety of parts which are to be heat-treated will be shown in combination with the required process and the furnace design. Fasteners, for example, usually have to be tempered in seal quench furnace plants. For the large bearings different furnace types can be used; the advantages and disadvantages of the different concepts will be discussed. Big gears are usually hardened by induction with a single tooth hardening. A very important, time and money consuming process is the case hardening of gear wheels and shafts, which are usually carburised in vertical pit-type furnaces. Alternative concepts like big seal quench furnaces or ring hearth furnaces will be presented and discussed. It will be shown that the ring hearth furnace allows similar heat treatment costs in comparison with pit-type furnaces. Furthermore, ring hearth and seal quench furnaces allow a fully automatic production and improved quality of the heat treatment results. The quenching of just one or two gear parts per load in a CFD optimised quenching tank will help to reduce distortions. So it should be possible to reduce the grinding costs, and, furthermore, to reduce the required case depth and to save carburising time.     

ZG40MnB钢的制备及组织研究

通过加入锰、硼合金用中频感应炉熔炼制备ZG40MnB钢,对其进行了退火热处理试验。用金相显微镜观察铸态及热处理后的试样组织。通过金相组织分析,铸态组织为铁素体+珠光体,退火组织为均匀的铁素体+珠光体+硼化物。     

3种浸锑石墨材料的摩擦磨损性能实验研究

利用S250 Mk3扫描电镜和WJ-10B型万能材料试验机对EK3205、M170D和T163D 3种浸锑石墨材料组织结构、机械性能和摩擦磨损性能进行了对比试验。试验结果表明：3种材料成分和组织结构基本相同,机械性能和磨损性基本相当;T163D和M170D摩擦因数(0.130和0.135）要比EK3205的(0.140）低;基体材料越致密,孔隙分布越均匀,添加超细粉因体有利于润滑膜的形成与稳定,有利于减小摩擦因数。     

The use of a new type of large vacuum batch furnace for the heat treatment of moulds and dies

The primary focus in vacuum heat treating of dies for the die casting industry is to reduce distortion, while obtaining a smooth surface finish with no post cleaning needed and easy process control. A slower gas quenching reduces distortion, but special larger dies show grain boundary precipitation with the consequence of a shorter die life. — With the increased use of high-pressure gas quenching and faster quench rates for moulds and dies, the quality of heat treatment has improved significantly over the last ten years. With quicker quench rates, distortion and post machining increased which, however, was accepted in return for the improvement in lifetime despite an increased risk of quench cracking. This paper discusses the vacuum heat treating of moulds and dies (over 5 metric tons) in the newly developed Super Turbo^TM vacuum furnace with 15·10⁵ Pa nitrogen gas quench combined with directional cooling.     

Computational study of gas quenching on carburizing hypoid ring gear

Due to its pure convective heat transfer, flexible process parameters, and clean nontoxic quenching medium, gas quenching has become a solution to traditional quench distortion and growing environmental problems. To further improve the productivity of gas quenching, the present quench pressure and flow velocity have been increased to five or more times greater than those common 10 to 20 years ago. Thus, the nonuniformity problem of gas quenching has arisen. Previous works have shown that, by varying the quench pressure, flow velocity, gas type, rack design, and furnace ducts, the uniformity of gas quenching process can be improved. In this paper, the relationships among gas pressure, flow velocity, and cooling-speed uniformity were investigated by CFD analysis coupled with experimental validation. Results indicate that the uniformity of the gas-quenching process can be improved by increasing the quench pressure and decreasing the flow velocity. This can be explained by the smoother gas flow around parts treated with higher quench pressure and lower flow velocity. In addition, it is found from the obtained results that the configuration of parts may influence the cooling capability and uniformity of a gas-quenching process significantly.     

45钢亚温淬火工艺可减少淬火开裂倾向

亚温淬火条件下,淬火温度和回火温度对45钢强度及硬度有影响,分析了亚温淬火后的组织与性能。实验发现,在740~800℃,随淬火温度的升高,其强度和硬度升高,并减少了淬火裂纹。     

固体渗硼剂的研制

渗硼层质量的高低取决于渗硼剂及催渗剂的效果。研究表明,采用B4C作为硼源,配合KBF4作为催渗剂,再加入5%~10%的硼酸做添加剂,可以得到渗层较深且渗层缺陷较少的渗层。