DIWA

The high-temperature structural steel: DIWA

DIWA has been specially developed as a structural steel for steam-boilers and pressure vessels for elevated service temperatures. DIWA is available in three levels of hot yield strength, the definitive material characteristic parameter for such applications. All three DIWA versions are significant improvements over the standardized materials otherwise used in this sector. The DIWA grades have low manganese, copper, nickel and molybdenum contents, and achieve their ultimate properties as a result of the heat treatment that concludes their production. Like all Dillinger Hütte GTS steels, DIWA grades have exceptionally good workability and, above all, weldability.

DIWA 353 withstands operating temperatures of up to 400° C and can, for example, be used in the steam drums of subcritical power-generating plant systems. This steel is usually supplied in normalized and tempered state, in plate thicknesses ranging from 6 to 150 millimeter. DIWA 353 is based on the standardized 13MnNiMo5.4 grade (Material No. 1.8807), VdTüV Material Data Sheet 384.

DIWA 373 can be used for temperatures up to 500° C and is suitable for use in boilers and piping systems. It is available in thicknesses up to 250 millimeter. Up to a thickness of 180 millimeter, it is supplied in normalized and tempered state, and above this thickness, water-quenched and tempered. DIWA 373 is based on the standardized 15NiCuMoNb5 grade (Material No. 1.6368), EN 10028, Part 2.

DIWA 393 is used where combined resistance to elevated temperatures (up to 375° C) and elevated pressures is required, in nuclear power plant engineering, for example, in urea and methanol production, and in the manufacture of synthetic fuels. This steel is supplied in water-quenched and tempered state in thicknesses up to 250 millimeter. DIWA 393 is based on the standardized 20MnMoNi4.5 grade (Material No. 1.6311), EN 10028, Part 2.