Alloy compositions

Abstract

The present disclosure provides compositions comprising iron, about 0.01 to about 0.4% w/w of manganese; about 1.3 to about 1.9% w/w of chromium; about 0.10% w/w or less of nickel; about 1.2 to about 1.7% w/w of molybdenum; about 0.01 to about 0.4% w/w of niobium; about 0.01 to about 0.4% w/w of vanadium; about 1.5 to about 2% w/w of silicon; and about 0.01 to about 0.20% w/w of carbon. The present disclosure also provides methods of preparing a metal powder, comprising atomizing a composition described herein and methods of preparing a metal object, comprising subjecting metal powder described herein to metal binder jetting.

1 . A composition comprising iron and:
 about 0.01 to about 0.4% w/w of manganese;   about 1.3 to about 1.9% w/w of chromium;   about 0.1% w/w or less of nickel;   about 1.2 to about 1.7% w/w of molybdenum;   about 0.01 to about 0.4% w/w of niobium;   about 0.01 to about 0.4% w/w of vanadium;   about 1.5 to about 2% w/w of silicon; and   about 0.01 to about 0.20% w/w of carbon.   
     
     
         2 . The composition of  claim 1 , comprising 0% w/w of nickel. 
     
     
         3 . The composition of  claim 1 , comprising about 0.04 to about 0.1% w/w of nickel. 
     
     
         4 . The composition of  claim 1 , comprising about 0.1 to about 0.3% w/w of manganese. 
     
     
         5 . The composition of  claim 1 , comprising about 1.4 to about 1.8% w/w of chromium. 
     
     
         6 . The composition of  claim 1 , comprising about 1.3 to about 1.6% w/w of molybdenum. 
     
     
         7 . The composition of  claim 1 , comprising about 0.1 to about 0.3 w/w of niobium. 
     
     
         8 . The composition of  claim 1 , comprising about 0.1 to about 0.3 w/w of vanadium. 
     
     
         9 . The composition of  claim 1 , comprising about 1.5 to about 1.8% w/w of silicon. 
     
     
         10 . The composition of  claim 1 , comprising about 0.05 to about 0.14% w/w of carbon. 
     
     
         11 . The composition of  claim 1 , further comprising sulfur. 
     
     
         12 . The composition of  claim 11 , comprising about 0.001 to about 0.015% w/w of sulfur. 
     
     
         13 . The composition of  claim 1 , further comprising oxygen. 
     
     
         14 . The composition of  claim 13 , comprising about 0.01 to about 0.1% w/w of oxygen. 
     
     
         15 . The composition of  claim 1 , further comprising nitrogen. 
     
     
         16 . The composition of  claim 15 , comprising about 0.01 to about 0.02% w/w of nitrogen. 
     
     
         17 . The composition of  claim 1 , that is a metal powder. 
     
     
         18 . The composition of  claim 1 , having a d 10  particle size of about 1 to about 10μ, a d 50  particle size of about 10 to about 20μ, or a d 90  particle size of about 20 to about 30μ, or combinations thereof. 
     
     
         19 . A method of preparing a metal powder, comprising atomizing the composition of  claim 1 . 
     
     
         20 . The method of  claim 19 , wherein the atomizing is gas or water atomizing. 
     
     
         21 . A metal powder prepared according to the method of  claim 19 . 
     
     
         22 . The metal powder of  claim 21 , having a d 10  particle size of about 1 to about 10μ, a d 50  particle size of about 10 to about 20μ, or a d 90  particle size of about 20 to about 30μ, or combinations thereof. 
     
     
         23 . A method of preparing a metal object, comprising subjecting the metal powder of  claim 19  to metal binder jetting. 
     
     
         24 . The method of  claim 23 , comprising depositing two or more layers comprising the metal working composition of  claim 1  onto a substrate. 
     
     
         25 . The method of  claim 24 , wherein the layers are bound together using a liquid binding agent. 
     
     
         26 . The method of  claim 23 , further comprising sintering the metal object. 
     
     
         27 . The method of  claim 26 , wherein the metal object is sintered at a temperature region at which the crystal structure of the alloy is body centered cubic (BCC) ferrite. 
     
     
         28 . The method of  claim 26 , wherein the sintered metal object comprises an about 1:1 ratio of BCC to face centered cubic austenite (FCC). 
     
     
         29 . The method of  claim 26 , wherein the sintering temperature is about 700 to about 1500° C. 
     
     
         30 . The method of  claim 26 , wherein the density of the sintered metal object is at least about 7 g/cm 3 . 
     
     
         31 . The method of  claim 26 , wherein the sintered metal object is annealed. 
     
     
         32 . The method of  claim 31 , wherein the intercritical annealing temperature is about 600 to about 1000° C. 
     
     
         33 . A metal object prepared according to the method of  claim 23 .