形变对低碳微合金化热处理钢组织和性能的影响

对比研究了在线淬火+回火工艺和传统调质工艺对低碳微合金化船体结构用钢组织和性能的影响,并探讨了其强韧化机制。结果表明,相对于传统调质工艺,采用在线淬火+回火工艺时,控制轧制产生的形变结构提高了在线淬火冷却过程中的相变驱动力和形核率,获得了精细的板条贝氏体组织,并且有利于形成纳米级析出相和高密度位错,从而提高了低碳微合金化钢强度,又保证了良好的低温韧性,总体性能(R_p0.2=599 MPa,KV₂(-40 ℃)=272 J/cm²,A=24.5%)达到了590 MPa级船体用钢要求。

Effect of deformation on microstructure and properties of low-carbon microalloyed steel

Effect of online quenching and tempering process and conventional quenching and tempering process on microstructure and properties of a low-carbon microalloyed hull structural steel was comparatively investigated, and the strengthening and toughening mechanisms were discussed. The results show that compared with conventional quenching and tempering process, when the online quenching and tempering process is adopted, the deformation structure generated by the controlled rolling improves the phase transformation driving force and nucleation rate during the online quenching and cooling process, and fine bainitic lath is obtained. It is beneficial to the formation of nano-scale precipitates and high-density dislocations, thereby improving the strength of the low-carbon microalloyed steel and ensuring good low-temperature toughness. The overall performance (R_p0.2=599 MPa,KV₂(-40 ℃)=272 J/cm²,A=24.5%) meets the requirements of the 590 MPa class hull steel.