Moly-steel

Benzene Cast Iron Cast Iron Carbon Steel Nickel Moly. Steel Ring Packing... 

OD Tube Gauge Factor Carbon Steel Admiralty Red Brass,. 45% Ars. Copper 4-6% Chrome V2 % Moly Steel 80-20 CU-NI 70-30 CU-NI Monel Copper 99.9+ % CU Nickel Aluminum Stainless AISI Type 302 304 Yorkalbro, Aliun. Brass... 

M. Prager, Hydrogen Attack Susceptibility Of Chrome-Moly Steels And Weldments, PVP Vol. 239/MPC Vol. 33, Serviceability of Petroleum, Process, and Power Equipment, American Society of Mechanical Engineers, New York, 1992. 

Swedish chemist Carl Wilhelm Scheele Hard silvery metal mined from the ore molybdenite added to steel as moly steel to increase ability to withstand pressure and temperature shifts in auto and plane engines. 

Chrome-moly steels have % to 9% chromium and either % or 1% molybdenum. Chromium increases scaling resistance and molybdenum improves or provides elevated temperature strength. Carbon content is kept low to maintain weldability. Chrome-moly steels are widely used for piping and pressure vessels operating up to 1000°F in environments such as steam or hydrogen and are available in many product forms. The two most popular alloys are 1 chrome- moly and 2 chrome-1 moly. 

Many metals look alike. It is relatively easy to substitute the wrong metal when the identification has been obliterated or the accompanying paperwork lost. For example, chrome-moly steels look like carbon steel, are magnetic, and rust like carbon steel if stored outdoors. Chrome-moly steels are used in critical applications such as piping for handling steam or hydrogen. Carbon steel should not be mistakenly substituted for chrome-moly steel in a critical application, because it might fail catastrophically. 

In an effort to solve the problem of carbon fonna-tion without resorting to the use of high cost stainless steels, a sample of chrome-moly steel ws subjected to the alonizing process (aluminum impregnation). Table VII demonstrates the successful pacification of the surface ... 

Caibon steel (C.S.) Carbon-moly steels (through 3% Cr.)... 

A simple, low cost steel for high temperature service in electric power generation (qv) is the C—0.5% Mo steel known as carbon—half moly, which was widely used for many years. The power industry and oil refineries have turned to 1.25% Cr—0.5% Mo and 2.25% Cr—1% Mo steels for high stress and high temperature service, because these steels have improved resistance to graphitization and oxidation, as weU as higher creep and mpture strength. 

Shafts are made of material ranging from medium carbon to low alloy steel and are usually heat treated. Shafts were originally made of forgings for the compressors in process service. But because of the availability ot high quality material, hot rolled bar stock has been used for shafts up to S inches in diameter. Bar stock shafts are given the same heat treatment and quality control as forgings. Many of the process users prefer a low alloy, chrome-moly-nickel material for shafting, particularly for compressors in critical service. 

Gold, Monel, Inconel, nickel-moly- bdenum alloys Cupronickels silver solder. Copper Steel... 

For added corrosion and temperature resistance, the nickel content of tubes, and sometimes the Moly (molybdenum) content as well, are increased. Tubes with a high nickel content are classified as 300 series stainless steels. A 0.5 percent silicon content is used to enhance the tube s oxidation or exterior scaling resistance. 

Knockout drums handling gas with particulates are usually better off without a demister, unless there is a provision to backwash the demister. The demister must be made out of a corrosion-resistant material. In many refinery services, a high-molybdenum-content (high-moly) stainless steel is sufficient. 

Normally a steel is considered in tins category if it has a yield strength of 160,000 psi or more. The first of these steels to be produced was a chromium-molybdenum alloy steel, shortly followed by a stronger chromium-nickel-moly bdenum grade. 

Chemistry. Chemical analysis methods range all the way from simple to sophisticated. See Chapter 6 under Field Identification. The exact chemical composition is generally not required. The identification method should distinguish the correct material from materials that may have been substituted. For example, a moly (molybdenum) spot test is a chemical color change technique that is sometimes used to distinguish 304 (no moly) from 316 (small percentage of moly) stainless steel. 

Field Identification. Supplemental chemistry verification by x-ray fluoresence spectroscopy or chemical spot test (e.g., for moly in 316 stainless steel) may be required. 

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