Q345D seamless steel pipe 42Cr2Mo steel is ultra-high strength steel, with high strength and toughness, good hardenability, no obvious temper brittleness, small deformation during quenching, high fatigue limit and high resistance after quenching and tempering. Secondary impact ability, good impact toughness at low temperature, high creep strength and durable strength at high temperature. The steel is usually quenched and tempered after surface quenching as a heat treatment scheme.


Physical properties:


1) Critical point temperature (approximate value): Ac1=730°C, Ac3=800°C, Ms=310°C.


2) Linear expansion coefficient: temperature 20~100°C/20~200°C/20~300°C/20~400°C/20~500°C/20~600°C, linear expansion coefficient: 11.1×10K /12.1×10K/12.9×10K/13.5×10K/13.9×10K14.1×10K.


3) Elastic modulus: temperature 20°C/300°C/400°C/500°C/600°C, elastic modulus 210000MPa/185000MPa/175000MPa/165000MPa/15500oMPa


Q355D seamless steel pipe is made by stacking low carbon steel or low alloy tool steel strip steel according to a certain vortex line angle (called forming angle) into pipe material, and then welding the pipe seams. Hot-rolled strip production manufactures large-diameter seamless tubes. Q355D seamless steel pipe is mainly used for the transportation of crude oil and gas, and its specifications and models are indicated by the diameter and wall thickness. Q355D seamless steel pipe has single-layer welding and double-sided welding. The welded steel pipe should ensure that the compression test, welding compressive strength and cold drawing characteristics meet the requirements