Microstructure distribution and bending fracture mechanism of 65Mn steel in the laser surface treatment

Revealing the Enhancement Mechanism of Laser Cutting on the Strength–Ductility Combination in Low Carbon Steel

“…The SCLS sample shows the high- The peak temperature gradually decreases along with the increase in the depth from the laser cutting surface, which is similar to the characteristics of the welding thermal cycle [24,25]. Considering that the relatively high peak temperature occurs at the position near the laser cutting surface [26], the prior austenite grain size of layer I is greater than the other regions of the HAZ. On the contrary, part of the ferrite and pearlite transform to the austenite in layer III.…”

Control of the metallographic and mechanical properties of Cr8 cold-work die steel by laser continuous/dispersed quenching

“…Unnotched impact specimens with dimensions of 10 mm×10mm× 55mm were used in this work [8,19], and the hardened layer was on the opposite side with pendulum during the impact test, as shown in Figure 5. The quasi-static three-point bending tests (Figure 6) were carried out by mechanics teste, according to the Chinese Standard GB/T229-2006 [7]. In which the quenched spots were placed on the tension side, and the center of the quenched spot was aligned with the axis of the load head, as shown in Figure 2(c).…”

“…Then, the ultimate bending strength (UBS), bending yield strength (σb0.2) and fracture strain (εf) were obtained, and the fracture work (W) could be calculated as Eq. ( 3) [7,8,20].…”

“…The fracture mechanism of LCQ and LDQ is summarized and depicted in Figure 18, elucidating the underlying physical processes involved. Firstly, under the influence of the axial stress σa generated by the deformation, the surface of the hardened on the tensile side attains the fracture strength, where the crack generates, as shown in Figure 18(1-a) [7]. Owing to the high brittleness of the hardened layer, the crack formed on the outer surface of the hardened layer.…”

“…Meanwhile, it is also placed on high expectation in the modern high-performance vehicle high-strength steel parts stamping production [2,5]. During actual use, the surface of the mold to withstand the impact and high stress can easily give rise to fatigue fracture and small chipping [6][7][8][9]. Consequently, this necessitates that the molds possess superior characteristics such as high strength, high hardness, exceptional wear resistance, and sufficient toughness [3,6].…”