Profile clamp

Abstract

A steel profile clamp is used to join flanged component parts. The profile clamp has at least partially conical side walls that are bent radially inwardly. The profile clamp has welding joints to maintain the shape of the clamp. The steel is martensitic for increased load-carrying capacity of the joint. The steel material, in an ambient temperature range of 20° C. to 750° C., has a coefficient of thermal expansion that is at least 0.3×10 −6 m/mK lower than that of the coefficient of thermal expansion of a ferritic casting material. The method for manufacturing the profile clamp includes prequenching and tempering the material of the profile clamp when it is in the form of a strip. After forming and welding the profile clamp, the weld is subject to induction tempering.

What is claimed is:  
     
         1 . A profile clamp for joining flanged components, said profile clamp being at least partially circular and having conical side walls that are bent radially inwardly, said profile clamp being made of steel having, at an ambient temperature of 20° C. to 750° C., a coefficient of thermal expansion that is lower by at least 0.3×10 −6  m/mK than a coefficient of thermal expansion of a ferritic casting steel.  
     
     
         2 . The profile clamp according to  claim 1 , wherein the profile clamp is comprised mainly of iron, the remaining constituents, in percent by weight, being: 
 up to 0.45% C, up to 2.0% Si, up to 2.0% Mn, up to 0.04% P, up to 0.04% S, 15 to 20% Cr, from 1 to 8% Ni, up to 2.5% Mo, up to 0.5% V, up to 0.1% Al, up to 0.1% Co, up to 0.4% Cu, up to 0.4% Pb, up to 0.1% Se, up to 0.1% Te, up to 0.5% Ti, up to 0.1% W, up to 0.05% Zr, up to 0.01% O, up to 0.01% N, up to 0.1% Bi, up to 0.001% B, up to 0.05% Nb.    
     
     
         3 . The profile clamp according to  claim 2 , wherein the maximum amount of C is 0.4%, of Si 0.5%, of Mn 0.8%, and of Mo 2.0%, and the minimum amount of Mo is 0.3% and of V 0.25%.  
     
     
         4 . The profile clamp according to  claim 1 , further comprising: 
 at least one clamping band having end sections that are bent radially outwardly and back to form a loop at each end section, said end sections being welded to said clamping band;    a bolt being disposed with each loop, each loop having a slit extending around a major portion of said bolt;    a headed bolt having a shaft, said shaft of said headed clamping bolt extending through said slits in said loops;    at least one partially circular ring segment being welded to a radial inner surface of said at least one clamping band, said at least one partially circular ring segment including said conical walls so that, in axial cross-section, said partially circular ring segment is approximately hat-shaped, said conical side walls having a plurality of reinforcements; wherein, one of said bolts disposed within each of said loops has an approximately tear drop shape in axial cross-section with its sides enclosing a right angle, one of the sides of said one bolt extending approximately radially outwardly away from the clamp circumference and the other side of said one bolt extending in the circumferential direction of the clamp, the loop surrounding said one of said bolts being shaped to match the tear drop cross-section of said one of said bolts, said clamping bolt head being supported on a side of said loop that extends radially outwardly away from the clamp circumference.    
     
     
         5 . The profile clamp according to  claim 1 , further comprising: 
 at least one circular ring segment having end sections that are bent radially outwardly and back to form a loop at each end section, said end section being welded to said circular ring segment;    a bolt being disposed within each loop, each loop having a slit extending around a major portion of said bolt;    a headed clamping bolt having a shaft, said shaft of said headed clamping bolt extending through said slits in said loops;    wherein, said at least one circular ring segment includes said conical side walls so that, in axial cross-section, said circular ring segment is approximately hat-shaped, said conical side walls have a plurality of reinforcements, one of said bolts disposed within each of said loops has an approximately tear drop shape in axial cross-section with its sides enclosing a right angle, one of the sides of said one bolt extends approximately radially outwardly away from the clamp circumference and the other side of said one bolt extends in the circumferential direction of the clamp, the loop surrounding said one of said bolts being shaped to match the tear drop cross-section of said one of said bolts, said clamping bolt head being supported on a side of said loop that extends radially outwardly away from the clamp circumference.    
     
     
         6 . The profile clamp according to  claim 4 , wherein said reinforcements are formed by sheet metal welded to said conical side walls.  
     
     
         7 . The profile clamp according to  claim 5 , wherein said reinforcements are formed by sheet metal welded to said conical side walls.  
     
     
         8 . The profile clamp according to  claim 6 , further comprising a plain washer having a diameter larger than that of the head of said headed clamping bolt, said plain washer being disposed between said head of said headed clamping bolt and said one of said loops supporting said headed clamping bolt.  
     
     
         9 . A system comprising of a profile clamp and flanged components, the flanged components being made of a ferritic casting material, said profile clamp being at least partially circular and having conical side walls to be joined by said clamp and being bent radially inwardly, said profile clamp being made of steel having, at an ambient temperature of 20° C. to 750° C., a coefficient of thermal expansion that is lower by at least 0.3×10 −6  m/mK than the coefficient of thermal expansion of said ferritic casting material.  
     
     
         10 . The system according to  claim 9 , wherein the flanged components are comprised mainly of iron, the remaining constituents, in percent by weight, being: 
 up to 5.0% C, up to 8.0% Si, up to 2.0% Mn, up to 3.0% Cr, up to 36% Ni, up to 2.5% Mo, up to 4.0% V, with any remaining constituents being less than 1.0%.    
     
     
         11 . A profile clamp for joining flanged components, said profile clamp being at least partially circular and having conical side walls that are bent radially inwardly, said flanged components being made of spheroidal graphite cast iron being comprised mainly of iron, the remaining constituents, in percent by weight, being: up to 5.0% C, up to 8.0% Si, up to 2.0% Mn, up to 3.0% Cr, up to 36% Ni, up to 2.5% Mo, up to 4.0% V, with any remaining constituents being less than 1.0%, said profile clamp being made of steel having, at an ambient temperature of 20° C. to 750° C., a coefficient of thermal expansion that is lower by at least 0.3×10 −6  m/mK than the coefficient of thermal expansion of said spheroidal graphite cast iron.  
     
     
         12 . The profile clamp according to  claim 11 , wherein the amount of C is between 1.0 and 5.0%, the amount of Si is between 1.7 and 8.0%, the amount of Mo is between 0.2 and 2.5%, the amount of Cr is between 0.2 and 2.8%, and the amount of V is between 0.2 and 4.0%.