物探冲击器活塞材料(T8A钢)的试验研究

Experimental study of piston material (T8A steel) of impactor used in geophysical prospecting

对物探冲击器活塞材料 (T8A钢 )的热处理工艺和抗冲击疲劳性能的试验研究结果表明 ,最佳热处理工序和工艺为调质处理预热淬火 (76 0℃× 2min)回火 (2 0 0℃× 1 5h) ;在这种工艺下 ,淬硬层深度为 2 5～ 3 2mm ,组织为回火马氏体 +细粒状碳化物 ,心部组织为屈氏体 +细粒状碳化物 ,这种组织既保证了表层的高硬度 ,又具有良好的综合力学性能 ,抗疲劳性能试验中多次冲击下凹值最小 ,麻点出现数目最少 ,有较好的多次冲击疲劳抗力。研制活塞实物的现场试验累计工作寿命达 4 0 0h ,抗冲击疲劳寿命大大提高。

An experiment is conduct to investigate the heat treatment technology and impact fatigue resistance of the piston material (T8A steel) of the impactor for geophysical prospecting. The result of the experiment shows that, the optimum heat treatment procedure and technology is: quenching and tempering→preheating→quenching(760℃×2 min)→tempering(200℃×1.5 h). With this technology, the depth of the hardened layer is 2.5～3.2 mm, and the microstructure and the cored structure are respectively tempered martensite + acinose carbide and, troostite + acinose carbide. This micostructure not only ensures high surface hardness, but also has excellent comprehensive mechanical property and good resistance to frequent impact fatigue. Field test shows that the impactor piston made of T8A steel has run for over 400 h in total.