| 摘要 |
A high strength non-thermal refining steel for hot forging which is easy to be separated into tow or more pieces by breaking and suitable for hot-forging connecting rods of the reciprocating engines for example, which consists by weight percentage of C: 0.30 SIMILAR 0.60 %, Si: 0.05 SIMILAR 2.00 %, Mn: 0.10 SIMILAR 1.00 %, P: 0.03 SIMILAR 0.20 %, Cu: 0.03 SIMILAR 0.50 %, Ni: 0.03 SIMILAR 0.50 %, Cr: 0.01 SIMILAR 0.50 %, V: 0.05 SIMILAR 0.50 %, s-Al: 0.010 SIMILAR 0.045 % and N: 0.005 SIMILAR 0.025 %. The hot forging forged in the hardness of 20 to 35 HRC using the above-mentioned steel is broken at a speed of not lower than 0.5 mm/s after forming a notch with a stress-concentration factor of not less than 2.0 in a length not less than 25 % of the length of the whole circumference of the fracture portion around the fracture portion to be separated. |
