论文部分内容阅读
利用H13棒材镦粗作为模具坯料,对镦粗后的模具坯料超声波探伤检测时发现部分坯料心部存在超标缺陷,不同部位钢材镦粗后缺陷大小有所差异。为查明缺陷原因,分别对原棒材及镦粗有缺陷坯料取样分析,利用金相显微镜、扫描电镜、电子探针显微分析仪等设备进行观察。结果表明密集粗大的一次碳化物是引起镦粗后心部缺陷的主要原因;钢锭冒口端钢材(冒口端)比非冒口端钢材(非冒口端)心部一次碳化物更密集、粗大,因此仅冒口端经镦粗后心部出现缺陷;冶炼时采用合理工艺参数是防止产生一次碳化物的主要手段;一旦出现一次碳化物,采用多次镦拔工艺成材可改善钢材心部质量。
The use of H13 bar upsetting as a mold blank, upsetting the billet after ultrasonic testing found that some blanks have excessive heart defects, different parts of the steel upset the size of the defects vary. In order to find out the cause of the defect, the original bar stock and the upsetting defective stock were sampled and analyzed respectively. The specimens were observed by metallographic microscope, scanning electron microscope and electron probe microanalyzer. The results show that the dense and coarse primary carbides are the main cause of the heart defects after upsetting. The riser end of steel riser is more dense than the primary carbides of the non-riser end (non-riser end) Thick, so only the riser after risking the Ministry of heart defects; smelting process parameters with reasonable to prevent the primary means of preventing the occurrence of a carbide; once a carbide, using multiple upsetting process can improve the quality of steel heart quality.