【摘要】 １８Ｃｒ－２Ｍｏ钢较低的塑性原与Ｃ，Ｎ，Ｓ间隙原子存在所形成的短程障碍有关，某些间隙相大厚片和小片群沿｛１００｝面大量析出，使钢在０℃下易产生解理断裂解理断裂；加Ｎｂ，Ｚｒ，Ｖ，Ｍｎ不能改善钢的韧性。加Ｔｉ因只析出有球化趋势的间隙相，并降低钢中自由Ｃ，Ｎ，Ｓ原子含量，有利于提高钢的塑性。更多还原

【Abstract】 The lower toughness of 18Cr-2Mo steel was related to the short-range obstruction formed due to ekisting C, N and S interstitial atoms in steel and precipitating thick lamellar and flaky phases along {100} plane, which caused cleavage fracture of steel at 0℃. Adding Nb, Zr, V and Mo has not been found to contribute to the toughness. Adding Ti caused spheroidal interstitial phases deposited and interstitial impurities decreased which contributed to the toughness of steel.更多还原