EPS处理对QStE700TM钢氢脆敏感性影响

Effect of Eco Pickled Surface Treatment on Hydrogen Embrittlement Sensitivity of QStE700TM Steel

采用慢应变速率拉伸(SSRT)和双电解池电化学氢渗透等手段,研究了湿法抛丸(EPS)、酸洗和干式抛丸3种表面处理工艺对QStE700TM高强结构钢氢脆敏感性及氢渗透动力学参数的影响规律;并结合不同处理工艺钢板试样表面氧化铁皮残留、硬度和残余应力变化,探讨了EPS工艺对QStE700TM钢氢脆敏感性影响机理。结果表明,EPS工艺处理QStE700TM钢试样的氢脆敏感性仅为8.1%,相较于酸洗和干式抛丸工艺分别降低了12.7%和20.5%。这与EPS工艺处理钢板表面氧化铁皮残留少,残余应力为-150~-300 MPa范围内的压应力有关。另外,EPS处理钢试样因更小的氢扩散通量(J∞L)和有效氢扩散系数(Dapp)及更大的滞后时间(tL)和阴极侧次表面氢浓度(c0),表现出比干式抛丸工艺处理钢试样更好的阻碍氢扩散性能,进而表现出更低的氢脆敏感性。综合考虑,EPS工艺是一种全新、可靠的和低碳环保的高强钢表面除鳞工艺。

The effect of surface treatments of Eco Pickled Surface(EPS),picking and blasting on the hydrogen embrittlement(HE)susceptibility and hydrogen permeation kinetic of QStE700TM highstrength structural steel was comparatively assessed via slow strain rate tension(SSRT)and double electrolytic cell electrochemical hydrogen permeation device.The influence of surface treatment processes on the HE susceptibility of QStE700TM steel was discussed in terms of the variations of residual oxide scale,hardness and residual stress on the surface of steel plates subjected to different surface treatments.The results showed that the HE susceptibility of QStE700TM steel treated by EPS technique was only 8.1%,which is 12.7%and 20.5%lower than that by pickling and blasting,respectively.It would be re-lated to the less residual oxide scale and the existed residual compressive stress on the surface of thesteel plate treated by EPS. In addition, smaller hydrogen diffusion flux (J∞L) and effective hydrogen diffusioncoefficient (Dapp) and larger lag time (tL) and cathode side subsurface hydrogen concentration (c0),should be responsible for the lower HE susceptibility of the steel samples treated by EPS. Take all factorsinto account, the EPS is a new, reliable, low-carbon and environmentally friendly surface descaling technologyfor high-strength steel.