A36 mill certificate steel plate, Q345C steel plate is a kind of weldable low carbon engineering structure material, which is generally produced by continuous rolling mill. The carbon content of Q345C steel plate is less than 0.25%. The yield strength σ0.2 of Q345C steel plate is 300- 800MPa and the yield ratio is 0.65- 0.95. Q345C steel plate has excellent low temperature toughness. That is mainly owe to the solid solution of alloy elements (Mn, Si, Al, Cr, etc.), grain refinement (Nb, V, Ti, etc.), precipitation hardening (Nb, V, Ti, etc.), phase transformation strengthening (Mn, Si, Mo, etc.), and controlled rolling and controlled cooling, etc. new technologies.
Normalizing of steel plate is a heat treatment method that heats the A36 mill certificate steel plate steel above the critical temperature so that all the steel is transformed into uniform austenite and then cooled naturally in the air.It can eliminate the network cementite of the hypereutectoid steel, for the hypoeutectoid steel normalization can refine the lattice, improve the comprehensive mechanical properties, for the parts with low requirements of normalization instead of annealing process is more economic.
Advantages of hot rolling: hot rolling can destroy the casting structure of ingot, refine the grain of steel and eliminate the defects of microstructure, so that the steel structure is dense and the mechanical properties are improved. This improvement is mainly reflected in the rolling direction, so that the A36 mill certificate steel plate steel is no longer isotropic to some extent; the bubbles, cracks and looseness formed during pouring can also be welded under the action of high temperature and pressure.
The A36 mill certificate steel plate steel plate generally adopts the process routes of concentrate feeding into furnace - smelting (converter, electric furnace - microalloying treatment - argon blowing -LF refining - low superheat continuous casting (feeding rare earth wire)- controlled rolling and controlled cooling.
