【摘要】 采用5.0kW横流CO2激光器对电冶钢结硬质合金DJW40表面进行重熔处理。对重熔区显微组织进行了研究,研究表明:激光重熔区分为熔凝区、过渡区及热影响区;熔凝区组织细小且致密,由粘结相和碳化物构成;大颗粒碳化钨部分溶解,小颗粒碳化物完全溶解;相比于基体,过渡区碳化物数量增多,过渡区的厚度与激光扫描速度成相反的变化;热影响区为相变硬化区,小颗粒碳化物有所增多。激光重熔可以大大改善电冶钢结硬质合金表面的组织结构。更多还原

【Abstract】 DJW40 samples by means of electro-slag and casting were melted by transverse flow CO2 laser with the maximum power of 5.0kW. The result of microstructures analysis show: there are melted zone , transient zone and heat affected zone in the laser melted layer. In the melted zone ,the microstructures are refined, which consist of carbides and bond phases. Big WC particulates dissolved partially ,while fine carbides dissolved completely .The numbers of Carbide become more in transient zone than the substrate ,and so are in the heat affected zone. The depth of transient zone is in reverse to the laser scan velocity. Solid phase transformation happened in the heat affected zone. In a word, surface micro- -structure of DJW40 can be improved by laser surface melting.更多还原