First, what are the details of the hardenability guarantee and quality requirements for seamless steel pipes?
- 20CrMnTiH seamless steel pipe: This type of steel guarantees hardenability. Its hardenability is clearly limited, with minimal variation between batches, making it suitable for mass production. Its deformation pattern is stable. Upon delivery, it must meet strict hardenability standards, meaning the hardness of the cross-section after quenching must be between the upper and lower limits (H-band) of the hardenability curve (H-curve). This strict control ensures the consistency and reliability of material properties.
- 20CrMnTi seamless steel pipe: This type does not guarantee hardenability. Its batch-to-batch dispersion is greater, and its deformation pattern is unstable. Upon delivery, the main guarantee is that the chemical composition meets the standards, but there are no specific requirements for hardenability.

Second, what are the details of the chemical composition and cost of seamless steel pipes?
- 20CrMnTiH seamless steel pipe: To improve the hardenability of the steel, steel mills may appropriately increase the content of alloying elements such as Cr and Mn, which may lead to an increase in cost. Meanwhile, to meet hardenability requirements, stricter requirements are placed on indicators such as inclusions and grain size in the steel.
- 20CrMnTi seamless steel pipe: Its chemical composition meets basic standards, but strict control over hardenability is not required; its cost is relatively low.

Third, what are the application scenarios and material selection recommendations for seamless steel pipes?
- 20CrMnTiH seamless steel pipe: Due to its stable hardenability, it is suitable for manufacturing parts with high performance consistency requirements, such as small module gears. In these applications, using 20CrMnTiH seamless steel pipe can reduce quality problems caused by fluctuations in material properties.
- 20CrMnTi seamless steel pipe: It is more suitable for occasions where hardenability requirements are not high, or when production batches are small, and cost is more sensitive. In these cases, using 20CrMnTi seamless steel pipe can meet basic performance requirements while reducing costs.

Fourth, what are the details of the processing and deformation characteristics of seamless steel pipes?
- 20CrMnTiH seamless steel pipe: Due to its stable hardenability, the processing deformation pattern is also relatively stable. This helps to predict and control the amount of deformation during processing, improving processing accuracy and efficiency.
- 20CrMnTi seamless steel pipe: Due to the large dispersion in hardenability, the processing deformation pattern may also fluctuate significantly, which increases the uncertainty and difficulty in the processing.