Reciprocating piston pump surface treatment process

Abstract

A process for treating rods and cylinders for use in reciprocating piston pumps is provided which yields a substantial increase in wear over the chrome coatings of the prior art. A base material of stainless steel 17-4ph is heat treated in the range generally from H-900 to H-1150. Once the material is pretempered, an ion nitriding process is applied. With this process, the hardness can be increased from the standard 17-4 hardness of RC-44 max to a desired hardness of RC-65 to 75.

What is claimed is:  
     
         1 . In a reciprocating piston pump for use with paints and coatings, said pump having at least one of a piston rod and cylinder, the improvement comprising treating at least one of said rod and cylinder with an ion nitriding process.  
     
     
         2 . The reciprocating piston pump of  claim 1  wherein the base material for at least one of said rod and cylinder is a 17-4ph stainless steel.  
     
     
         3 . The reciprocating piston pump of  claim 1  wherein the base material for at least one of said rod and cylinder is treated via ion nitriding to a hardness of about RC-65 to 75.  
     
     
         4 . The process of treating at least one of a reciprocating piston pump rod and cylinder formed of a base material and comprising the steps of: 
 heat treating the base material to a hardness of about H-900 to H-1150; and    ion nitriding said material to a hardness of about RC-65 to 75.