In this work, the hot deformation behavior of 30Cr4MoNiV ultra-high-strength steel is investigated by isothermal compression tests using the Gleeble-3500 thermal simulation machine (Dynamic Systems Inc., New York, NY, USA) at a temperature range of 1173–1373 K under the strain rate of 0.01–10 s⁻¹. A constitutive equation with strain-dependent constants and processing maps suitable for 30Cr4MoNiV ultra-high-strength steel are established. The results show that the combination of the hyperbolic sine function and the Zener-Hollomon parameter can accurately represent the influences of deformation temperature, strain rate, and strain on the flow stress of the 30Cr4MoNiV ultra-high-strength steel. The applicability of plastic instability criteria such as m, $\dot{m}$, S, $\dot{S}$ and the instability parameter ξ are analyzed, the stability and instability regions are clarified accurately, and the optimized processing regions are given in the stability regions. The optimized regions are verified by the uniform equiaxed grains, and the plastic instability is validated by dynamic strain aging and the microstructure of the voids.

The variable cross-sectional shape of the blank reduces the efficiency of the sawing machine. Additionally, the wear of the band saw blade causes a mismatch between the feed rate and the load, further exacerbating the wear. This study studied a feed rate control strategy considering sawtooth wear to balance the relationship between cutting efficiency and band life. Initially, speed parameters for the cut-in and cut-out areas, along with acceleration and deceleration control algorithms, were established to ensure the smooth transition of the saw blade during the machining process. Additionally, a constant power sawing feed rate model that considers the influence of wear was developed, enabling dynamic adjustments to the feed rate based on the saw blade’s wear state. This study also proposes a fuzzy control-based target current correction method, which dynamically adjusts the target current according to the current wear state of the saw blade, ensuring that sawing requirements were met under varying levels of wear. The accuracy of the sawing model and control strategy was verified through experiments. The results demonstrated that this strategy improved efficiency by 44% compared to the traditional uniform feed rate method. This study introduced a novel feed rate control strategy for sawing and offers an effective solution to the problem of saw tooth wear.

Bandsaw blades are typical band-shaped cutting tools that are characterized by their low stiffness and micro-level cutting depth, resulting in distinct wear mechanisms compared to rigid cutting tools. In this study, the wear curve and wear mechanisms of the bandsaw tooth during the bandsawing of Cr12MoV cold-working steel were investigated. The tool life was divided into two stages: a rapid wear stage (Stage I) and a homogeneous wear stage (Stage II). In Stage I, the wear was dominated by chipping, although multiple wear mechanisms were found due to their relatively low manufacturing accuracy compared to rigid cutting tools, which resulted in remarkable differences in the cutting depth of each tooth. In Stage II, abrasive and adhesive wear were the primary wear mechanisms instead of chipping, which was related to the microstructure of Cr12MoV. Furthermore, methods for increasing bandsaw performance were proposed, based on the tooth wear mechanisms.

Bandsaw blades are typical band-shaped cutting tools characterized by low stiffness and micro-level cutting depth, resulting in distinct wear mechanisms compared to rigid cutting tools. In this study, the wear curve and wear mechanisms of bandsaw tooth during the bandsawing of Cr12MoV cold-working steel was investigated. The tool life was divided into two stages: a rapid wear stage (Stage I) and a homogeneous wear stage (Stage II). In Stage I, the wear was dominated by chipping although multiple wear mechanisms were found due to the relatively poor manufacturing accuracy compared to rigid cutting tools, which results in remarkable differences among the cutting depths of individual teeth. In Stage II, abrasive and adhesive wear were the primary wear mechanisms instead of chipping, which was related to the microstructure of Cr12MoV. Furthermore, methods for increasing the bandsaw performance were proposed based on the tooth wear mechanisms.

Bandsaw blades are typical band-shaped cutting tools characterized by a low stiffness and micro-level cutting depth, resulting in distinct wear mechanisms compared to rigid cutting tools. In this study, the evolution of bandsaw tooth wear mechanisms during the bandsawing of Cr12MoV cold-working steel was investigated. The tool life was divided into two stages according to the tooth wear mechanism: a rapid wear stage (Stage I) and a homogeneous wear stage (Stage II). In Stage I, the wear mechanism was dominated by chipping, although multiple wear mechanisms were found because of the relatively poor manufacturing tolerance compared to rigid cutting tools, resulting in remarkable differences between the cutting depths of the individual teeth. In Stage II, abrasive and adhesive wear were the primary wear mechanisms instead of chipping, due to the decreased width and setting magnitude tolerance after Stage I. Furthermore, methods for increasing the bandsaw performance were proposed based on the tooth wear mechanisms.