Fast nanoindentation technology is a new method used to generate performance maps showing the hardness and elastic modulus distribution of each position, and it has become a research focus. In this paper, nanoindentation combined with scanning electron backscatter diffraction (EBSD) is used to analyze the micro-regional properties of single-phase interstitial-free (IF) steel. Hardness, elastic modulus and the orientation of a 200 μm × 200 μm area were characterized in situ. The relationships between hardness, elastic modulus and orientation were analyzed. The experimental results showed that the hardness varied from 1.25 GPa to 2.57 GPa, while the modulus varied from 122 GPa to 227 GPa with different crystallographic orientations. The hardness value of the (111) crystal plane was particularly high, with an average hardness of about 1.84 GPa, which is due to its higher work hardening rate. This result is consistent with the EBSD kernel average misorientation (KAM) micrograph. The harder locations with greater misorientation are more difficult to deform compared to locations with small hardness regions, for example, the (001) crystal plane. However, there seems to be no obvious strong relationship between modulus and orientation. The modulus of the regions with lower hardness seems to be smaller. The results of the KAM diagram are consistent with those of hardness mapping.

Failure analysis of 42CrMo cylinder bolt had been done through the chemical component analysis, tensile test, metallographic test and fracture morphology observation. It was identified brittle fracture. The crack was mainly intergranular and propagated to fracture. The results show that it is hydrogen induced delayed fracture.

Failure analysis of JL466Q crankshaft has been done through the chemical component analysis, mechanical properties testing, macrographic examination and microstructure analysis. The results show that crankshaft cracking is formed by quenching stress.