Abstract: A percussive drilling component includes a cylindrical male screw thread formed of a steel material. The thread includes thread crests and thread roots interconnected by thread flanks. To protect the thread against corrosion, the thread is coated with a material having a lower electrode potential than the steel material. The coating is situated at least in regions located radially inwardly of the thread flanks. The male screw thread can be attached to a female screw thread of another percussive drilling component, the female screw thread also being coated with the material.

Abstract: A compound tube including a layer of a Fe—Cr alloy and a layer of load-carrying component, with the optional addition of further layers. The Fe—Cr alloy preferably has a composition including, in weight-%: less than 0.3% carbon, 15-60% chromium, less than 10% nickel, less than 5% molybdenum, less than 5% silicon, less than 0.3% nitrogen, less than 5% manganese, and the remainder iron with naturally occurring impurities. The compound tubes are very resistant to carbonization and metal dusting, and are suited for use as bayonet tubing, superheater tubing, and reforming tubing in steam formation environments.

Abstract: A compound tube comprises a layer of a Fe—Cr—Al-alloy and a layer of a load-carrying component and optionally one or several additional layers. The Fe—Cr—Al-alloy has the following analysis in weight-%: carbon<0.3, chromium 5-30, nickel<10, manganese<5, molybdenum<5, aluminium 3-20 , silicon<5, nitrogen<0.3, cerium+bafnium+yttrium<1.0, titanium 0.005-1.0, zirconium 0.005-1.0, niobium 0.005-1.0, the remainder iron, and naturally occurring impurities. These tubes are very resistant towards carbonization and “metal dusting” and are being used to advantage for bayonet tubing, superheat tubing and reformer tubing in steam formation.

Abstract: The present invention relates to a martensitic, corrosion resistant steel for rock drilling with properties which is adjusted essentially with regard to resistance against corrosion fatigue. This has been obtained in that an elongated element for percusive rock drilling which includes at least a thread and a flush channel has been made with corrosion resistant steel having a mainly martensitic structure.

Abstract: A new austenitic stainless steel alloy is provided (in wt. %) according to the following analysis:C: less than 0.12%;Si: less than 1.0%;Cr: 16-22%;Mn: less than 2.0%;Ni: 8-14%;Mo: less than 1.0%;S: less than 0.03%;O: less than 0.03%;N: less than 0.05%;La: between 0.02% and 0.11%; andone of the following:(i) Ti in an amount at least 4 times the amount of carbon and 0.80% or less, or(ii) Nb in an amount at least 8 times the amount of carbon and 1.0% or less;the remainder Fe and normally occurring impurities. The new steel is particularly suitable as a super heater steel and a heat exchanger steel.

Abstract: A new austenitic stainless steel comprising in % by weight:C: <0.12,Si: <1.0,Cr: 16-22,Mn: <2.0,Ni: 8-14,Mo: <1.0,either Ti: >4% by weight of C and <0.8 or Nb: 8% by weight of C and <1.0,S: <0.03,O: <0.03,N: <0.05,REM: .ltoreq.0.30 and >0.10, and the remainder Fe and normally occurring impurities, REM being one or more of the elements Ce, La, Pr and Nd. The new steel is particularly suitable as a superheater steel and a heat exchanger steel.