（30~90）mm×（400~605）mm Cr12Mo1V1（D2）冷作模具扁钢的组织和性能

Structure and Properties of（30~90）mm ×（400~605） mm Cold-Working Die Flat Steel Cr12Mo1V1（D2）

试验用Crl2MolV1（D2）冷作模具扁钢（/%：1.50C,0.35Si,0.40Mn,12.00Cr,0.95Mo,0.80V）的生产流程为30 t EAF-LF-VD-3 t铸锭轧制-890℃退火工艺。研究了D2冷作模具钢的断面尺寸（/mm：30×400,70×360,90×605）对该钢组织、共晶碳化物的尺寸、分布以及不均匀度、冲击韧性的影响。结果表明,随着扁钢截面尺寸的减小,共晶碳化物的颗粒尺寸、形态以及分布均匀性得到改善,扁钢的碳化物级别由90 mm×605 mm扁钢的4~6级降至30 mm×400 mm扁钢的1~4级,冲击韧性提高;钢的心部共晶碳化物分布最差（4~6级）,边部最好（1~4级）,心部的冲击韧性明显低于边部。

The production flowsheet of test cold-working die flat steel Cr12Mo1V1（D2）（/%：1.50 C,0.35 Si,0.40 Mn,12.00 Cr,0.95 Mo,0.80V） is 30 t EAF-LF-VD-3 t ingot casting-rolling-annealing at 890 ℃ process.The effect of cross-section size（/mm：30 × 400,70 × 360 and 90 × 605） of cold-working die flat steel D2 on the size,distribution and uniformity of eutectic carbide,the structure and the impact toughness of steel has been studied.The results show that with decreasing the cross-section size,the size of particles,morphology and distribution uniformity of eutectic carbide in flat are improved,the rating of carbide in flat decreases from 4 ~6 rating of 90 mm ×605 mm flat to 1 ~ 4 rating of 30 mm ×400 mm flat,and the impact toughness of steel increases;the distribution of eutectic carbide at core of flat is worst（rating4 ~ 6） and that at edge is best（rating 1 ~ 4）,and the impact toughness of steel at core is obviously lower than that at edge.