CSP工艺生产硼微合金化SPHD板的组织性能

以CSP流程生产的含B和无B的SPHD冷轧基板为实验材料,运用拉伸实验、金相观察、SEM、TEM和EBSD手段,对比分析了两种钢的力学性能、组织、析出物、位错密度和晶体学取向的变化. 研究表明:微合金元素B的加入明显使SPHD冷轧基板的铁素体晶粒粗大化,钢中有粗大的析出相粒子产生,且位错密度下降,从而引起屈服强度的降低. 采用背电子散射EBSD技术分析了无B和含B钢的晶体学取向,其取向主要为大角度晶界,且无B钢中存在着大量的亚晶.

Microstructure and properties of SPHD hot strips with boron produced by CSP technology

B-contained(0.004%-0.006%) and B-free SPHD hot strips produced by CSP process were chosen as experimental materials.The mechanical properties,microstructure,precipitates,dislocation density and grain orientation of the two different kinds of specimens were analyzed by tensile tests,metallographic observations,SEM analysis,TEM and EBSD observations.The results showed that the addition of micro-alloying element B into SPHD hot strips made ferrite grains evidently coarse,large precipitates were found,the dislocation density decreased,and all these caused the yield strength to reduce.The crystallographic orientation was analyzed and observed by EBSD.The orientations among neighboring grains both of the B-contained and B-free steel were mainly large angle grain boundaries,however,a great deal of subgrains were found in the B-free steel.