D. Gear box: 200 Involute cylinder Bevel wheel, castalloysteel piston.
齿轮箱：200渐开线圆柱斜齿轮，铸造合金钢活塞。
2
The chemical compositions of new castalloysteel with high si content was designed, its microstructure and corrosion behavior were studied.
设计了一种含硅量较高的新型铸造合金钢，并研究了该合金钢的显微组织及其腐蚀行为。
3
The castalloysteel bit-sharpener has been prepared by pouring the chrome abrasion resistance steel and the low-alloysteel with fine impact resistance one-step using cast-in technique.