Impact toughness reflects the resistance of metal materials (seamless pipes) to external impact loads, generally expressed by impact energy (Ak), whose unit is J (joules).
Impact toughness refers to the ability of a material to absorb plastic deformation work and fracture work under impact load, reflecting the fine defects and impact resistance inside the material. The practical significance of the impact toughness index is to reveal the brittle tendency of the material and to reflect the resistance of the metal material to external impact loads. and J (joules). The factors that affect the impact toughness of steel are the chemical composition of the material, the heat treatment state, the smelting method, the inherent defects, the processing technology and the ambient temperature.
The impact energy test of
high-pressure seamless pipe (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 notched impact test two. Impact test: use a high-pressure seamless pipe sample of a certain size and shape (10×10×55mm) (with a "U" or "V"-shaped notch in the middle of the length direction, the notch depth is 2mm) to be impacted on the specified testing machine Experiment of breaking from the notch under load impact.
Shock Absorption Work Akv(u) - The work absorbed by a metal pattern of a certain size and shape when it is broken under an impact load. The unit is Joule (J).
The normal temperature impact test temperature is 20±5℃; the low temperature impact test temperature range is <15～-192℃; the high temperature impact test temperature range is 35～1000℃.
The cooling medium used in the low temperature impact test is generally non-toxic, safe, non-corroding metal and non-solidifying liquid or gas at the test temperature. Such as absolute ethanol (alcohol), solid carbon dioxide (dry ice) or liquid nitrogen atomizing gas (liquid nitrogen).
