Mn2钢低温韧性变化规律研究

对Mn2钢在不同热处理工艺、不同试验温度和不同试样状态下的冲击韧性进行了详细的分析,结果表明:CM690钢在900℃保温90 min水冷淬火,600℃保温90 min水冷回火,在保证钢材的强度满足要求的情况下,可获得良好的韧性;淬火水温超过30℃时,因钢的淬透能力下降,会强烈地降低钢的强度和韧性;钢中加入0.015%~0.025%的Ti,提高冲击韧性值35~40 J;对于CM490钢,若轧后空冷或堆冷,由于冷却速度较低,会获得铁素体+珠光体+贝氏体的混合组织,不利于提高钢材的韧性,而正火后其组织为铁素体+贝氏体,其冲击值比前两种状态高3~5倍。

Study on Variation of Low Temperature Toughness of Mn2 Steel

The impact toughness of Mn2 steel in different heat treatment process, different temperature and different sample status is carried on the detailed analysis and research. The results showed that： CM690 steel in 900 ℃ heat and preservation 90 min water quenching, 600 ℃ heat and preservation 90 min water tempering, under the condition of meet the requirements of ensuring the strength of the steel can obtain good toughness; During the quenching temperature exceeds 30 ℃, because steel hardening ability to drop, will strongly decrease the strength and toughness of steel; Adding 0.015%-0.025% of Ti in steel, can significantly improve the impact toughness value 35-40 J; For CM490 steel, if after rolling the air cooling or heap cooling, due to the low cooling speed, will be a mixture of ferrite ＋ pearlite ＋ bainite, which is not conducive to improve the toughness of the steel, and after normalizing its organization mixture is ferrite ＋ bainite, its impact value is higher three to five times than the first two state.