42CrMo seamless steel pipe is an ultra-high strength steel with high strength, toughness and good hardenability.
Purpose of 42CrMo seamless steel pipe: the special steel for bridge is "42CrMo", the special steel for automobile girder is "42CrMo", and the special steel for pressure vessel is "42CrMo". This kind of steel improves the mechanical properties of steel by adjusting the carbon content (c). Therefore, according to the carbon content, this kind of steel can be divided into: low carbon steel - the carbon content is generally less than 0.25%, such as 10 and 20 steel; Medium carbon steel - the carbon content is generally between 0.25 ~ 0.60%, such as 35 and 45 steel; High carbon steel - carbon content is generally greater than 0.60%. This kind of steel is not generally used in the manufacture of steel pipes.
It has obvious tempering brittleness and small deformation during quenching. After quenching and tempering treatment, 42CrMo seamless steel pipe plant has high fatigue limit and multi impact resistance, good impact toughness at low temperature, and high creep strength and lasting strength at high temperature. Surface quenching after quenching and tempering is usually used as the heat treatment scheme in 42CrMo seamless steel pipe plant.
42CrMo seamless steel pipe plant is divided into hot-rolled pipe, cold-rolled pipe and cold drawn pipe according to different production methods, with their own process regulations. The materials include ordinary and high-quality carbon structural steel (q215-a ~ q275-a and 10 ~ 50 steel), low alloy steel (09mnv, 16Mn, etc.), alloy steel, stainless and acid resistant steel, etc. According to the purpose, it is divided into general purpose (for water transmission, gas pipeline, structural parts and mechanical parts) and special purpose (for boiler, geological exploration, bearing, acid resistance, etc.).
Chemical composition (mass fraction) of 42CrMo seamless steel pipe: Ni ≤ 0.030%, P ≤ 0.030%, s ≤ 0.030%
42CrMo seamless steel pipe is a kind of steel. Steel used to be called steel. The method is called Q345B. The similar materials are Q345A, Q345C and Q345E. The quality grade symbol a, B, C, d e respectively indicates that impact test is not required. The impact test temperature is + 20 ° 0 ° to 20 ° 40 ° ABCD indicates the quality grade Q235. The quality grade is divided into four grades A, B, C and D. from a to D indicates that the quality is from low to high.
Requirements for different quality grades are as follows: a - provide s, P, C, Mn, Si chemical composition and Fu, FY δ 5（ δ 10) , 1800 cold bending test can be provided according to the buyer's needs, but there is no impact energy regulation, and the carbon content and manganese content are not taken as the delivery conditions. B - provide s, P, C, Mn, Si chemical composition and Fu, FY δ 5（ δ 10) , cold bending 180 'test'.
It also provides impact energy AK ≥ 27j at + 200C - in addition to the requirements of class B, it also provides impact energy AK ≥ 27j at 00C. D --- in addition to the requirements of class B, 42CrMo seamless steel pipe factory also provides impact energy AK ≥ 27j at - 200C e -- in addition to the requirements of class B, it also provides impact energy AK ≥ 27j at - 400C.