Stainless steel formulation for pump components

Abstract

A stainless steel formulation and fabrication of various hydraulic fracturing pump components using the stainless steel formulation is disclosed. The stainless steel formulation provides for a relatively high martensitic grain structure, which provides for high strength and durability, high wear tolerance, high chemical tolerance, and high hardness. Thus, pumps and/or pump components fabricated with the stainless steel formulation may have greater lifetimes than pumps and/or pump components fabricated from conventional materials. The stainless steel formulation also includes relatively wide ranges and tolerances of constituent elements. The wide tolerances enable and/or ease the use of scrap metals in formulating the stainless steel formulation, which provides for cost and environmental benefits. Pump components, such as a fluid end assembly, may be fabricated using the stainless steel formulation to realize usable lifetime, cost, and/or environmental advantages.

What is claimed is: 
     
         1 . A stainless steel formulation, comprising:
 a nickel (Ni) content in a range of about 3.5% to about 4.5% by weight;   a chromium (Cr) content in a range of about 12% to about 13.5% by weight;   a manganese (Mn) content in a range of about 0.5% to about 1.5% by weight;   a molybdenum (Mo) content up to about 0.7%;   a copper (Cu) content up to about 0.5% by weight;   a titanium (Ti) content in a range of about 0.005% to about 0.05% by weight;   a cobalt (Co) content in a range of about 0.04% to about 0.2% by weight; and   a vanadium (V) content in a range of about 0.03% to about 0.2% by weight.   
     
     
         2 . The stainless steel formulation of  claim 1 , further comprising:
 an aluminum (Al) content up to about 0.05% by weight;   a combined niobium (Nb) and tantalum (Ta) content up to about 0.1% by weight; and   a phosphorous (P) content up to about 0.035% by weight.   
     
     
         3 . The stainless steel formulation of  claim 1 , further comprising:
 a carbon (C) content of about 0.03% by weight;   a silicon (Si) content of about 0.4% by weight;   a Mn content of about 0.8% by weight;   a P content of up to about 0.03% by weight;   a Cr content of about 12.7% by weight;   a Mo content of about 0.5% by weight;   a Ni content of about 3.75% by weight;   a Cu content of up to about 0.25% by weight;   a combined Nb and Ta content of less than about 0.05% by weight;   an Al content of up to about 0.025% by weight;   a nitrogen (N) content of about 0.025% by weight;   a Ti content of up to about 0.01% by weight;   a Co content of up to about 0.1%; and   a V content of up to about 0.07%.   
     
     
         4 . The stainless steel formulation of  claim 3 , further comprising:
 trace levels of sulfur(S).   
     
     
         5 . The stainless steel formulation of  claim 1 , further comprising:
 a Si content up to about 0.6% by weight;   a C content up to about 0.05% by weight;   a Mo content in a range of about 0.3% to about 0.7% by weight; and   a N content in a range of about 0.02% to about 0.05% by weight.   
     
     
         6 . The stainless steel formulation of  claim 1 , further comprising:
 a P content in a range of about 0.025% to about 0.035% by weight;   a Cr content in a range of about 13.4% to about 13.5% by weight;   a Ni content in a range of about 4% to about 4.5% by weight;   a Cu content in a range of about 0.4% to about 0.5% by weight;   a combined Nb and Ta content in a range of about 0.05% to about 0.1% by weight; and   an Al content in a range of about 0.025% and about 0.05% by weight.   
     
     
         7 . The stainless steel formulation of  claim 6 , further comprising a Ti content in a range of about 0.01% to about 0.05% by weight;
 a Co content up to about 0.2% by weight; and   a V content up to about 0.2% by weight.   
     
     
         8 . The stainless steel formulation of  claim 1 , further comprising:
 a combined C and N content in a range of about 0.03% and 0.1% by weight.   
     
     
         9 . The stainless steel formulation of  claim 1 , further comprising:
 a combined Ti, Nb, and V content in a range of about 0.01% and about 0.15% by weight.   
     
     
         10 . The stainless steel formulation of  claim 1 , wherein stainless steel formulation is in a form of a component of a fluid end assembly of a pump. 
     
     
         11 . A method, comprising:
 providing an ingot, wherein the ingot includes:   a nickel (Ni) content in a range of about 3.5% to about 4.5% by weight,   a chromium (Cr) content in a range of about 12% to about 13.5% by weight,   a molybdenum (Mo) content up to about 0.7%; a manganese (Mn) content in a range of about 0.5% to about 1.5% by weight,   a copper (Cu) content up to about 0.5% by weight,   an aluminum (Al) content up to about 0.05% by weight,   a combined niobium (Nb) and tantalum (Ta) content up to about 0.1% by weight, and   a phosphorous (P) content up to about 0.035% by weight;   forging the ingot into a string; and   cutting the string into pieces.   
     
     
         12 . The method of  claim 11 , further comprising:
 performing a heat treatment on at least one of the string or the pieces:   tempering at least one of the string or the pieces; and   machining the pieces into one or more components of a hydraulic fracturing pump.   
     
     
         13 . The method of  claim 11 , wherein the ingot comprises:
 a titanium (Ti) content up to about 0.05% by weight;   a cobalt (Co) content up to about 0.2% by weight; and   a vanadium (V) content up to about 0.2% by weight.   
     
     
         14 . The method of  claim 11 , wherein the ingot comprises:
 a carbon (C) content of about 0.03% by weight;   a silicon (Si) content of about 0.4% by weight;   a Mn content of about 0.8% by weight;   a P content of up to about 0.03% by weight;   a Cr content of about 12.7% by weight;   a Mo content of about 0.5% by weight;   a Ni content of about 3.75% by weight;   a Cu content of up to about 0.25% by weight;   a combined niobium (Nb) and tantalum (Ta) content of less than about 0.05% by weight;   an Al content of up to about 0.025% by weight;   a nitrogen (N) content of about 0.025% by weight;   a Ti content of up to about 0.01% by weight;   a Co content of up to about 0.1%; and   a V content of up to about 0.07%.   
     
     
         15 . A fluid end, comprising:
 a component including:   a nickel (Ni) content in a range of about 3.5% to about 4.5% by weight,   a chromium (Cr) content in a range of about 12% to about 13.5% by weight,   a titanium (Ti) content up to about 0.05% by weight;   a cobalt (Co) content up to about 0.2% by weight; and   a vanadium (V) content up to about 0.2% by weight.   
     
     
         16 . The fluid end of  claim 15 , wherein the component is a body of the fluid end assembly. 
     
     
         17 . The fluid end of  claim 15 , wherein the component includes:
 a carbon (C) content of about 0.03% by weight;   a silicon (Si) content of about 0.4% by weight;   a manganese (Mn) content of about 0.8% by weight;   a phosphorus (P) content of up to about 0.03% by weight;   a Cr content of about 12.7% by weight;   a molybdenum (Mo) content of about 0.5% by weight;   a Ni content of about 3.75% by weight;   a copper (Cu) content of up to about 0.25% by weight;   a combined niobium (Nb) and tantalum (Ta) content of less than about 0.05% by weight;   an aluminum (Al) content of up to about 0.025% by weight;   a nitrogen (N) content of about 0.025% by weight;   a Ti content of up to about 0.01% by weight;   a Co content of up to about 0.1%; and   a V content of up to about 0.07%.   
     
     
         18 . The fluid end of  claim 15 , wherein the component includes:
 a combined Mo and tungsten (W) content in a range of about 0.32% to about 0.7% by weight.   
     
     
         19 . The fluid end of  claim 15 , wherein the component includes:
 a P content in a range of about 0.025% to about 0.035% by weight;   a Cr content in a range of about 13.4% to about 13.5% by weight;   a Ni content in a range of about 4% to about 4.5% by weight;   a Cu content in a range of about 0.4% to about 0.5% by weight;   a combined Nb and Ta content in a range of about 0.05% to about 0.1% by weight; and   an Al content in a range of about 0.025% and about 0.05% by weight.   
     
     
         20 . The fluid end of  claim 19 , wherein the component includes a J-factor below 350.