通过着色检测、宏观断口分析、扫描电镜分析及金相分析,对Q355B钢板超声波检测缺陷性质进行了分析.结果表明:无损检测缺陷性质为白点.结合白点的成因及Q355B钢板实际生产工艺情况,提出了针对性的工艺改进措施,取得了满意的效果.

40CrMnMoA辊轴锻件在锻后超声检测过程中发现内部存在连续性的超标缺陷.通过对其超标缺陷部位进行解剖定性分析,结果表明:40CrMnMoA辊轴锻件的缺陷为夹渣,夹渣的主要成分为Al、Si、Ca等元素.

某840离心铸造机用冷模在离心浇铸某高铬铸铁零件过程中发生开裂事故.在开裂冷模上取样检测,分析出导致冷模开裂的原因,并提出了针对性的预防措施和建议,避免了冷模早期开裂事故的再次发生.

材质为ZG45CrMo的矿用磨机铸钢大齿轮在使用过程中发生断齿失效现象.通过现场检测,宏观分析,并采用化学成分分析、力学性能检测、金相分析及微观断口分析等检测手段对断齿部位进行分析.结果表明:大齿轮结合面间隙过大,在啮合过程中非正常接触造成局部弯曲应力较大,是导致大齿轮断齿的主要原因,同时铸造疏松缺陷降低了大齿轮的疲劳寿命,促进了大齿轮早期疲劳裂纹产生.

通过一系列热处理工艺试验和力学性能测试,以及显微组织分析和断口扫描分析,研究了30CrMnSiNi2A钢不完全马氏体淬火所得组织与力学性能的关系.试验结果表明:通过900℃ ×60 min→油冷30～45 s→270～340℃ ×30 min→油冷至室温→270～340℃ ×120 min回火工艺的处理,可以使30CrMnSiNi2A钢获得组织细小均匀的板条马氏体加下贝氏体加残留奥氏体.多相复合组织的存在显著提高了该试验钢的强韧性,从而使其得到良好的综合力学性能.

本文通过断口形貌、化学成分、力学性能试验和金相检测等方法对加热炉炉筋管开裂原因进行分析.结果表明,焊接裂纹和气孔等缺陷的存在是导致其开裂的主要原因,管道力学性能不合格和滑块材料耐热性差、强度不高对其开裂也都有重要影响.

The phenomenon of point segregation and mechanical property instability often occurs in 30CrMnSiNi2A aerospace forgings produced by traditional process" EBT electric furnacet LF+VD+VC+forging". The forgings were studied by using eletroslag remelting (ESR)process. The uniformity and gas contents of consumable electrode and electroslag ingot composition, and the burning loss of elements in ESR process were discussed. The macrostructure and mechanical properties of the forgings were analyzed. The results show that, The composition uniformity of electroslag ingot is better than the uniformity of consumable electrode in double vacuum process, the burning of elements in electroslag remelting process is smaller, there is no spot segregation in macrostructure of forgings and the mechanical properties meet the technical requirements.

During the finish machining process , the cracks appeared on the end face and the outside surface of flange of rotor used for power station .For this reason, by means of macroscopic examination , chemical composition analysis, fracture analysis, metallographic examination and SEM analysis etc ., a comprehensive analysis has been carried out for defects .The results show that the exposed crack defects of rotor is caused by the nozzle clogging with slag inclusion which fell into the ingot during the pouring process .

对国外矿用磨机铸钢齿圈齿面进行磁粉检测分析,发现该磨机齿圈的很多齿面存在磁痕显示缺陷.挑选典型的缺陷位置,采用打磨处理、本体低倍组织分析、贴膜复型金相分析、硬度检测等一系列试验手段,判定了缺陷性质为铸态偏析和疏松. 结合大型铸件凝固原理以及在齿圈生产加工中所发现的实际案例,初步分析了缺陷的形成原因,并提出了针对性的改进措施.

通过低倍检验、电镜和金相分析等手段，对锻件缺陷进行了分析，结果表明锻件的缺陷为夹渣裂纹缺陷，其产生与钢液注锭温度偏低有关。

20CrNi2MoA钢齿轮轴锻件在第三次超声探伤过程中发现有4处严重超标缺陷.通过低倍检验、化学成分分析、金相检验和断口分析等方法对其超标缺陷进行了定性分析.结果表明:该缺陷为在氢和应力共同作用下产生的延迟性白点裂纹.

采用机械剥层和电解剥层相结合的剥层工艺,利用X射线应力分析仪研究了支承辊锻件表面中频感应淬火后的残余应力沿横截面的分布规律.结果表明:φ180 mm的45Cr4NiMoV钢支承辊表面中频感应淬火后表层为压应力,压应力层深约30 mm,从表往里逐渐由压应力转变为拉应力,拉应力峰值出现在距表面约60 mm处,不在支承辊锻件的中心部位.通过对支承辊锻件表面感应淬火后残余应力沿横截面分布规律的研究,可为生产特大型支承辊锻件制定合理的生产工艺方案提供可靠的试验依据.

Severe defect and its cause of 30CrMnSiA forging are analyzed by means of macro examination , chemi-cal composition analysis , macroscopic fractography , scanning electro microscope , and metallographic examination .The findings show that 30CrMnSiA forging has white spot defect is , white spot defect shall be avoided by strengthening the melting quality control .

选用不同钢种在不同加热温度条件下,采用比较法和截点法对两种常用的奥氏体晶粒度显示方法,即氧化法和晶粒边界腐蚀法进行了对比性研究.结果表明:氧化法显示钢的奥氏体晶粒度的准确性能够满足生产检验的要求,氧化法与晶粒边界腐蚀法所显示的奥氏体晶粒平均弦长的差值会受钢种及加热温度的影响.

35CrMo support-wheel shaft forgings in the second inspection process are found to have serious exceed standard defects.The serious defective parts are performed anatomical qualitative analysis by means of macrostructure test,macro-fracture analysis,chemical analysis,metallographic analysis and electron microscope(SEM) analysis.The results show that 35CrMo support-wheel shaft forging defect is the flake crack distributed in the area of segregation.

Defects which was suspected as inclusion were found after rough machining by ultrasonic testing in the ZCuSn10Zn2 centrifugal casting products.The property and reason of the defects were analyzed and judged by means of macroscopic inspection,chemical composition analysis and metallographic examination.The results showed that the property of the defects were structure segregation.The segregation defects were eliminated by heat treatment method,and resulting in the much increase of synthesis mechanical property of the alloy.

This paper has introduced the production process of 125 t steel ingot and cylinder forgings.The internal quality of the rush off part of cylinder forgings has been analyzed by dissection test.The results show the 125 t steel ingot internal metallurgical quality was good,and the forging process was suitable.