Component for supercritical water oxidation plants, made of an austenitic stainless steel alloy

Abstract

The present invention relates to a component with improved corrosion resistance for use in supercritical water oxidation plants. The component is made of an austenitic stainless steel alloy comprising 15-30% Cr and 20-35% Ni.

1 : A component for use in supercritical water oxidation plants, made of an austenitic stainless steel alloy comprising; in weight-%
 15 to 30% chromium; and   20 to 35% nickel,   
       wherein the component is intended to be in direct contact with supercritical or near supercritical solution. 
     
     
         2 : A component of  claim 1 , wherein the alloy comprises, in weight-%:
 15 to 30% chromium;   20 to 35% nickel; and   0.5 to 6.0% copper.   
     
     
         3 : A component of  claim 1 , wherein the alloy further comprises 0.01 to 0.10% carbon. 
     
     
         4 : A component of  claim 1 , wherein the alloy further comprises not more than 4.0% molybdenum. 
     
     
         5 : A component of  claim 1 , wherein the alloy further comprises 0.2 to 0.6% niobium. 
     
     
         6 : A component of  claim 1 , wherein the alloy comprises 0.4 to 4.0% tungsten. 
     
     
         7 : A component of  claim 1 , wherein the alloy comprises 0.10 to 0.30% nitrogen. 
     
     
         8 : A component of  claim 1 , wherein the alloy further comprises 0.5 to 3% cobalt. 
     
     
         9 : A component of  claim 1 , wherein the alloy comprises 0.02 to 0.10% titanium. 
     
     
         10 : A component according to  claim 1 , being in the form a plate, a tube, a bar, a rod, a strip, a foil, a lining, a sleeve, a block, a wire, a beam, a girder, a pillar, or a web. 
     
     
         11 : A component according to  claim 10  wherein the component is at least a part of a reactor, an oxygen tank, a sludge water tank, a vaporizer, an economizer, a steam boiler, a cooler, a gas/liquid separator, a valve, an accumulator, a pressure reduction device, a fluid oscillator, an injector, a nozzle, a filter or a trap. 
     
     
         12 : Use of an austenitic stainless steel alloy comprising 15-30% Cr and 20-35% Ni in supercritical water oxidation plants. 
     
     
         13 : Use of an austenitic stainless steel alloy according to  claim 12 , wherein the austenitic stainless steel alloy is intended to be in direct contact with supercritical or near supercritical solution. 
     
     
         14 : Use of an austenitic stainless steel alloy according to  claim 12  wherein the austenitic stainless steel alloy comprise (by weight): 20 to 35% nickel; 15 to 30% chromium; 0.5 to 6.0% copper; 0.01 to 0.10% carbon; 0.20 to 0.60% niobium 0.4 to 4.0% tungsten; 0.10 to 0.30% nitrogen; 0.5 to 3.0% cobalt; 0.02 to 0.10% titanium; not more than 4.0% molybdenum; not more than 0.4% silicon; and not more than 0.6% manganese, the balance being iron and normal steelmaking impurities. 
     
     
         15 : A supercritical water oxidation plant, comprising a component made of an austenitic stainless steel alloy comprising; in weight-%:
 15 to 30% chromium; and   20 to 35% nickel,   
       wherein the component is in direct contact with supercritical or near supercritical solution.