直接切削用40MnVS钢高强韧化控轧控冷工艺开发

采用1030℃开坯、880℃连轧、轧后穿水的控轧控冷工艺试制了Ф110 mm直接切削用40MnVS非调质圆钢，结果表明：轧后穿水可在控轧工艺的基础上进一步细化晶粒，明显改善带状组织，提高钢的力学性能。产品在抗拉强度达到945 MPa、屈服强度达到800 MPa的情况下，A_ku仍能达到70 J以上，可代替42CrMo等调质钢。

Development of High Strengthening and Toughening TMCP of 40MnVS Steel Round Bars for Direct Cutting Appliction

Using Theno-Mechanicd Control Process(TMCP)of 1030 ℃ breakdownrdling 800 ℃ continous rolling and water through after rolling,φ110& mm non-quench and tempering (NQT) 42MnVS for free cutting application was trial produced. The results indicate that water fast cooling process of rolled steel can refine grain size, improve banded structure obviously and increase mechanical properties of steel. At the condition that tensile strength reaches 945 MPa and yield strength reaches 800 MPa, the impact energy A_ku of steel products can still reaches more than 70 J. It can be used to replace 42CrMo NQT steel.