Nb-V复合非调质钢锻后组织变化

Microstructure change of Nb-V composite non-quenched and tempered steel after forging

在Gleeble-3800热模拟试验机上进行热变形试验,研究Nb-V复合非调质钢在不同锻造工艺下的组织变化规律。结果表明,相对于单独添加V的非调质钢,Nb-V复合非调质钢锻后晶粒细小,铁素体含量增多,呈块状均匀分布,珠光体片层间距减小,且片层分布不规则,可改善钢的组织韧性。降低冷却速度有利于先共析铁素体长大,促使网状铁素体向块状铁素体转变,分布更均匀,有利于非调质钢韧性的改善。增大锻后变形量,可使组织细化。

Hot compression experiments were carried out to study the effect of forging process on microstructure of Nb -V non-quenched and tempered steel on Gleeble-3800 thermal simulation machine .The results show that compared with non-quenched and tempered steel with single V adding , after forging , the grain size of Nb-V alloyed non quenched and tempered steel is fine , and blocky ferrite content increases and uniformly distributes , the pearlite interlamellar spacing decreases and distributes randomly , that improves the toughness of the steel . Reducing the cooling speed is in favor of proeutectoid ferrite growth , promote net ferrite transform to blocky ferrite and more uniform distributed, which is beneficial to improve the toughness of the steel .Increasing forging deformation can make the microstructure fines .