Abstract: A bainitic steel comprising, in weight % (wt %) C: 0.16-0.23, Si: 0.8-1.0, Mo: 0.67-0.9, Cr: 1.10-1.30, V: 0.18-0.4, Ni: 1.60-2.0, Mn: 0.65-0.9, P: 50.020, S: 50.02, Cu: <0.20, N: 0.005-0.012, balance Fe and unavoidable impurities.

Abstract: An elongate drill component for percussive drilling includes a female threaded end having an outer diameter (Dot), a male threaded end, and a central section between the ends having an outer diameter (Doc). The outer diameter of the female threaded end is larger than the outer diameter of the central section. A through-going flushing channel includes a central flushing channel having a diameter (Dic) and thread flushing channels having a diameter (Dit). The ratio of an elastic section modulus of a threaded joint measured when the female threaded end is connected to the male threaded end of an identical component to an elastic section modulus of the central section, St/Sc, is more than 1.5 and in that a ratio of the diameter of the central flushing channel to the outer diameter of the central section, Dic/Doc is between 0.45 and 0.95.

Abstract: An elongate drill component for percussive drilling includes a female threaded end having an outer diameter (Dot), a male threaded end, and a central section between the ends having an outer diameter (Doc). The outer diameter of the female threaded end is larger than the outer diameter of the central section. A through-going flushing channel includes a central flushing channel having a diameter (Dic) and thread flushing channels having a diameter (Dit). The ratio of an elastic section modulus of a threaded joint measured when the female threaded end is connected to the male threaded end of an identical component to an elastic section modulus of the central section, St/Sc, is more than 1.5 and in that a ratio of the diameter of the central flushing channel to the outer diameter of the central section, Dic/Doc is between 0.45 and 0.95.

Abstract: A bainitic steel comprising, in weight % (wt %): C: 0.16-0.23, Si: 0.8-1.0, Mo: 0.67-0.9, Cr: 1.10-1.30, V: 0.18-0.4, Ni: 1.60-2.0, Mn: 0.65-0.9, P: ?0.020, S: ?0.02, Cu: <0.20, N: 0.005-0.012 balance Fe and unavoidable impurities.

Abstract: An elongated percussive rock drilling element comprises at least one thread portion and a flush channel. At least the thread portion is made of a corrosion resistant steel having a structure with a martensite content greater than about 50 wt-% and less than about 100 wt-%, in which the steel comprises C+N greater than about 0.1 wt-% and less than or equal to about 0.8 wt-% and Cr greater than or equal to about 11 wt-% or Cr greater than or equal to about 5 wt-%, Mo less than or equal to about 5 wt-%, W less than or equal to about 5 wt-%, Cu less than or equal to about 2 wt-%, Mo+W+Cu greater than about 0.5 wt-% or Cr+3.3 (Mo+W)+16N greater than about 10 wt-%. The surface of said at least one thread portion of said corrosion resistant steel is ball blasted.

Abstract: A drill member for percussive rock drilling is formed by forming a compound component and friction welding the compound component to the end of a drill rod. The compound component is formed by welding a core part within a shell part and machining a thread into either the shell part (male thread) or core part (female thread). The part in which the thread is machined is formed of low alloy steel, and the other part is formed of stainless steel, wherein the thread bottom is formed of stainless steel, and the thread crests are formed of low alloy steel.

Abstract: A drill bit intended for percussive rock drilling is formed to reduce the occurrence of cavitation during percussive drilling. The drill bit includes an integral skirt and at least one channel for transport of flush medium, such as water. The drill bit has a front face provided with buttons, which define a greatest first external diameter (D0). A recess with a female thread, such as a rope or trapezoid thread for percussive drilling, extends into the drill bit from a rear end face of the drill bit. The recess has an axial depth (L0). The external surface of the skirt includes a conical portion having an axial extension that is greater than one-eighth of the depth (L0) of the recess but smaller than the depth (L0) of the recess.

Abstract: A drill member for percussive rock drilling is formed by forming a compound component and friction welding the compound component to the end of a drill rod. The compound component is formed by welding a core part within a shell part and machining a thread into either the shell part (male thread) or core part (female thread). The part in which the thread is machined is formed of low alloy steel, and the other part is formed of stainless steel, wherein the thread bottom is formed of stainless steel, and the thread crests are formed of low alloy steel.

Abstract: A percussive rock drill bit includes a head portion with a forward surface surrounded by a peripheral surface. The peripheral surface supports a wreath of peripheral buttons. Front buttons are mounted to the forward surface inside the wreath of peripheral buttons. The button shave a diameter (D) and a height (H), wherein H/D<1.2. The buttons are welded to an essentially flat part of the forward surface whereby the buttons are metallurgically bound to the head portion.

Abstract: A rotary cone drill bit includes at least one leg carrying a journal provided with bearing surfaces cooperating via bearing elements with bearing races in a rotatable cone cutter. The cone cutter is provided with rows of crushing elements. Each crushing element has a greatest width (D) and a greatest height (H), wherein HID<1.2. The crushing elements are welded to the body of the cone cutter to form a metallurgical bond therewith.

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: 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.