Base metal for high-toughness clad steel plate giving weld with excellent toughness, and process for producing clad steel plate

Abstract

The invention provides a base metal for high-toughness clad steel plates that give welds with excellent toughness. The base metal is characterized by containing, in terms of mass%, 0.030-0.10% of C, 0.10-0.30% of Si, 1.00-1.60% of Mn, up to 0.015% of P, up to 0.003% of S, and less than 0.010% of V and further containing one or more elements selected from 0.05-0.50% of Mo, 0.010-0.060% of Nb, 0.005-0.020% of Ti, up to 0.040% of Al, 0.0010-0.0040% of Ca, and 0.0030-0.0060% of N, with the balance being Fe and unavoidable impurities. The base metal is further characterized by having a percent ductile fracture of 85% or higher in a -20 DEG C drop weight tear test (DWTT) and having a value of vE-20 DEG C, measured at a location 3 mm apart from the heat affected zone (HAZ), of 100 J or more.

Description

technical field [0001] The present invention relates to a base metal of a high-toughness clad plate having excellent weld toughness and a method for producing the clad plate. Background technique [0002] In recent years, due to energy problems, energy development has also been carried out in areas called difficult-to-exploitation environments that were previously impossible to extract. Such an environment is a particularly severe corrosive environment (high-corrosive environment), and there is an increasing demand for high-alloy steel clad steel with better corrosion resistance. In addition, as the demand for industrial equipment and structures in a difficult-to-mine environment, aiming at achieving durability, long life, and maintenance-free, Ni-based alloys or Ni alloys represented by Alloy625 and 825 are materials that meet these needs and received attention. [0003] On the other hand, the prices of Ni, which is the main raw material of the Ni alloy, and alloy element...

AI Technical Summary

Problems solved by technology

However, the method disclosed in Patent Document 3 requires an additional step of reheating to a temperature of 1150° C. or lower, and thus causes an increase in manufacturing cost, and has problems in terms of industrial implementation.

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