The company adheres to the marine grade KD32 hull steel plate external market, internal management, quality and efficiency oriented development path, and has achieved good economic and social benefits. With strong financial strength, advanced management experience, excellent sales service, strict quality management system and scientific overall marketing means, we will work hand in hand with you for common development. We are making all efforts working on the optimization of marine grade KD32 hull steel plate quality and price and best service for all our customers.
After quenching and tempering, the 40Cr alloy steel plate has good comprehensive mechanical properties, good low-temperature impact toughness and low notch sensitivity. The hardenability of steel is good. It can be hardened to Ф28～60mm in water quenching and Ф15～40mm in oil quenching. In addition to quenching and tempering, 40cr sheet is also suitable for cyanidation and high-frequency quenching.
The yield point of the steel structure determines the stress that the structure can withstand without permanent deformation. The minimum yield point of typical carbon structural steel is 235MPa. The minimum yield point of typical low-alloy high-strength steel is 345MPa. Therefore, according to the proportional relationship of its yield point, the use of low-alloy high-strength steel allows the stress to be 1.4 times higher than that of carbon structural steel. Compared with marine grade KD32 hull steel plate, carbon structural steel, the use of low-alloy high-strength steel can reduce the size of structural parts and reduce weight.
marine grade KD32 hull steel plate annealing is to heat the steel to 30 ~ 50℃ above the critical temperature, keep it in the heat treatment furnace for a period of time, and then cool it down to room temperature with the furnace. The purpose of marine grade KD32 hull steel plate annealing is to refine the grain of steel, eliminate internal stress and reduce hardness, improve cutting performance, increase toughness and plasticity, and facilitate welding and rolling processes. marine grade KD32 hull steel plate annealing can be complete annealing, incomplete annealing, stress relief annealing, isothermal annealing and spheroidizing annealing.
Chemical composition of Q420 steel: C ≤ 0.20, Si ≤ 0.50, Mn ≤ 1.70, P ≤ 0.035, S ≤ 0.035, Nb ≤ 0.07, V ≤ 0.20, Ti ≤ 0.20, Cr ≤ 0.30, Ni ≤ 0.80, Cu ≤ 0.30, N ≤ 0.015, Mo ≤ 0.20. The mechanical properties of Q420 steel are: yield strength ≥ 340 MPa, tensile strength 500-680 MPa, elongation after fracture ≥ 18%, impact energy 34J. marine grade KD32 hull steel plate, Q420 steel has good mechanical properties and weldability, good cold and hot workability. Q420 steel is mainly used for manufacturing mining machinery, heavy vehicles, ships, bridges, medium and high pressure boilers, vessels and other large welding and structural parts.
Our company will accept the product quality objection registration record, pass it to the marine grade KD32 hull steel plate production unit and relevant departments, and timely coordinate the supervision of product marine grade KD32 hull steel plate quality objection. Our company coordinates the relevant department personnel to the customer unit to carry on the investigation, the processing.
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