What is the impact toughness of high-pressure seamless pipes?

Impact toughness reflects the ability of a metal material (seamless pipe) to resist external impact loads. It is generally expressed as impact energy (Ak) in J (Joules).

Impact toughness refers to the material's ability to absorb plastic deformation work and fracture work under impact load, reflecting the subtle defects and impact resistance within the material. The actual significance of the impact toughness index is to reveal the brittleness tendency of the material and reflect the ability of the metal material to resist external impact loads. and J (Joule). Factors that affect the impact toughness of steel include the chemical composition of the material, heat treatment status, smelting method, inherent defects, processing technology and ambient temperature.

The impact energy test of high-pressure seamless pipes (referred to as "impact test") is divided into three types: normal temperature, low temperature, and high temperature impact test due to different test temperatures; 》Shape notch impact test 2. Impact test: adopt a certain size and shape (10× 10 × 55mm) high-pressure seamless pipe specimen (with a "U" or "V" shaped notch in the middle of the length) and a notch depth of 2mm) are impacted on a specified testing machine and are tested to break from the notch under load impact. .

Impact absorbed work Akv(u) - the work absorbed when a metal model of a certain size and shape breaks under impact load. The unit is joule (J).

The normal temperature impact test temperature is 20±5℃; the low temperature impact test temperature range is