ductileadj.易延展的；柔软的；易教导的ductile fracture criterion韧性断裂准则ductile brittle transition延性 脆性转移ductile bridging injecting小导管加密注浆ductile grouting technology小导管注浆技术ductile deformation episode塑性形变幕ductile fracture initiation延性起裂ductile-brittle transiton韧脆转变ductile cast iron as-cast铸态可锻铸铁ductile cast iron pipelines铸铁管线ductile hard magnetic alloys可变形硬磁合金