高应力区沿空留巷围岩现状监测研究与分析

陈四楼矿计划实施沿空留巷的2802运输巷，断层较多，直接顶厚度较大，巷道矿压显现较为明显。针对顶板下沉、两帮外鼓、顶板淋水较大、巷道顶板受压破碎、金属网锈蚀严重、压脱锚杆较多、两帮位移较大等现象，提出在高应力区采用矿压监测的方法，通过对巷道变形现状进行的监测分析，对巷道破坏变形程度有了清晰的认识，对造成巷道破坏变形原因和影响因素有了详细的分析，根据注浆加固可改善围岩结构，提高围岩承载能力及锚杆、锚索锚固性能，是一种较为有效的围岩控制措施，确定了需要采用注浆加固的方式对进行巷道围岩破坏变形治理，并根据现场实际情况对注浆材料的性能提出了要求。     

Alloy optimisation of bainitic steel for large plastic mould

Based on the phase transformation theories, especially the T₀ concept of bainite transformation, alloy optimisation of bainitic steel with carbides has been carried out aiming at the produce of plastic mould with large cross-section. The effect of manganese and silicon on proeutectoid ferrite and bainite transformation is explored by dilatometric analysis, XRD and different microscopy techniques. The results show that after the alloy optimisation, the transformation of proeutectoid ferrite is suppressed and when the cooling rate is lower than 0·1°C?s^??1, the new lower bainite transformation appears by decreasing carbon capacity of austenite and promoting carbide precipitation. Industrial production proves that the optimised alloy SDP1 can meet the demand for the plastic mould with the thickness of 1050?mm.     

Model of Primary Austenite Dendrite Structure in Hypoeutectic Cast Iron

Ｉｔｗａｓｒｅｐｏｒｔｅｄ[1] ｔｈａｔｔｈｅｍｉｃｒｏ ｓｔｅｒｅｏｓｔｒｕｃｔｕｒｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｉｎｃａｓｔｉｒｏｎｃｏｎｓｉｓｔｓｏｆｐｒｉｍａｒｙｓｔｅｍｓａｎｄｓｅｃｏｎｄａｒｙａｒｍｓｔｈａｔ ｇｒｏｗａｃｃｏｒｄｉｎｇｔｏｄｅｎｄｒｉｔｅｃｒｙｓｔａｌｓｂｒａｎｃｈｒｕｌｅ ,ａｎｄｓｏｍｅｏｆｐｒｉｍａｒｙａｕｓｔｅｎｉｔｅｅｖｅｎｈａｖｅｔｈｉｒｄａｒｍｓ .ＭｉｙａｋｅＨｅｔａｌ[2 ]ｐｒｏｐｏｓｅｄａｃｏｎｃｅｐｔｏｆｒｅｇｉｏｎｍｏｄｅｌｂｙｓｔｕｄｙｉｎｇ…     

Influence of the Preheat Treatment on the Microstructure and Properties of X37CrMoV5-1 Steel

The technological properties of the hot-work tool steels depend on their microstructural quality induced by the production process and the heat treatment. One of the frequently applied methods to improve microstructure is preheat treatment. The treatment of carbonitriding X37CrMoV5-1 steel has been investigated in fluidized bed furnaces. Thickness and phase composition have been conducted using optical microscopy Neophot 32 and scanning microscopy, JEOL 5400, after etching in nital.     

不锈钢绕带容器环板与绕带端头的焊接

本文通过焊接试验对奥氏体不锈钢绕带容器环板与绕带焊接工艺进行了研究分析,并得出了合理的焊接方法和工艺参数。     

残留奥氏体对1500MPa级新型低碳Mn-Si-Cr系合金钢冲击韧度的影响

15 0 0MPa级无碳化物贝氏体 马氏体复相钢的第一类回火脆性开始温度高于 36 0℃。实验表明 ,这并非由于贝氏体 马氏体复相韧化 ,而是与无碳化物贝氏体中的膜状残留奥氏体有关。无碳化物贝氏体中机械稳定性较高的残留奥氏体可能是导致无碳化物贝氏体 马氏体复相钢第一类回火脆性开始温度升高的直接原因。     

Ti/Al Interaction and Austenite Grain Control in Crankshaft Manufacturing with 38MnSiVS5 Steel

38MnSiVS5 steel is similar to 38MnVS6 steel (EN), the difference being the addition of a small Ti content. Typical Ti and Al contents in the chemical composition of 38MnSiVS5 steel are Ti=0.020 and Al=0.035 mass%. Both elements combine easily with nitrogen, especially Ti, and it has been observed that relatively high Al levels are harmful for austenite grain size control at reheating temperatures. In this work 38MnSiVS5 steel is used to manufacture a large number of castings, varying only the Ti and Al contents and obtaining ingots with a different Ti/Al ratio in each case. The results show that abnormal growth of the austenitic grain occurs irrespective of the Ti and Al contents, due fundamentally to the partial dissolution and coarsening of TiN precipitates. However, the steels with high Al contents present worse behaviour due to the formation of a second type of precipitates, namely AIN, which quickly dissolve between 1000 and 1100°C, causing a drastic decline in local pinning forces that gives rise to more pronounced abnormal growth of the affected grains.     

不锈钢网架结构试验研究

对奥氏体不锈钢网架结构的物理力学性能、焊接性能加以分析，并进行了不锈钢焊接空心球节点承载力试验，确定了该种节点的受拉和受压承载能力。在此基础上，又做了不锈钢组合扭网壳模型的破坏性试验研究，试验结果与理论计算值比较，吻合较好。     

凸轮的表面裂纹分析

本文对一凸轮的表面裂纹进行了分析。渗碳后表层残余奥氏体含量过高级网状碳化物导致该凸轮在精磨过程中出现了磨削裂纹，本文还提出了二次回火或冰冷处理等改进措施来防止磨削裂纹的产生。