Custom Stainless Steel Valve Cover Castings And Heat-resistant Stainless Steel Castings Process

Product Detail

CORROSION RESISTANT STEEL GRADES

MARTENSITIC

A protective passive oxide film can develop on steels with chromium contents above 12%, imparting to these steels “stainless” characteristics. By maintaining a suitable composition balance between carbon and chromium, a series of high strength stainless steels are produced (R23-R23XHC).

Components cast in these alloys meet specific hardness and wear resistance criteria through closely controlled heat treatment practices. Alloy toughness and versatility are enhanced by additions of nickel and molybdenum (R24).




PRECIPITATION HARDENING

Strength and corrosion resistance superior to many martensitic stainless steel alloys is achieved by precipitation hardening a low carbon martensitic or semi-martensitic stainless steel (R27-R28). This is accomplished by accurate alloying and a low temperature heat treatment, allowing machined parts to be age hardened with only minimal distortion and scaling. Depending upon the particular alloy composition and heat treatment programme, precipitation hardening stainless steels can be supplied with appropriate hardness differentials to avoid galling and seizing during metal to metal contact




AUSTENITIC

Austenitic stainless steels are very tough and essentially non-magnetic alloys that are alloyed to produce resistance to corrosion in a variety of environments.

The basic 18% chromium/10% nickel grade (R31) has a very good corrosion resistance in many applications. This alloy can be refined (R31LC) or alloyed with molybdenum (R33,R34) for enhanced corrosion resistance or modified for improved welding (R30) and machining (R32) characteristics. Increasing nickel content and alloying with molybdenum and copper results in greatly improved corrosion resistance in more aggressive environments such as hot sulphuric acid (R36,R37).




DUPLEX

Duplex stainless steels comprise a mixture of ferrite and austenite, producing a alloy with many of the advantages offered by both structures (R29). They generally have comparable or better corrosion resistance to austenitic steels, with more than twice the yield strength, and are especially resistant to pitting corrosion and stress corrosion cracking in chloride environments.

Duplex alloys are made to a wide range of internationally recognised and proprietary specifications, through precise control of alloying content of both primary and trace elements and tailored heat treatment. Thus a series of duplex alloys develops with each grade processing specific characteristics such as Pitting Resistance Equivalent, yield strength and ferrite austenite ratio to suit a particular application.




NICKEL AND COBALT ALLOYS

The 99.5% cast nickel grade (R48) is designed to resist hot caustic solutions and can be alloyed to increase strength. Nickel-copper Monel type alloys (R47) have very good resistance to chloride corrosion. This grade can be supplied with additional silicon and age hardened (R47S) for increased strength where erosion-corrosion and galling occur in chloride containing media. The nickel-molybdenum-chromium (R39) Hastelloy type grades provide unique corrosion resistance to hydrochloric, phosphoric and hydrofluoric acid. QC R39 can additionally be alloyed with one or a combination of tungsten, vanadium, niobium, copper, tin and bismuth to produce metals with increased strength, high temperature capabilities, improved corrosion resistance and anti-galling properties.




STAINLESS STEEL GRADES

R22Grade 420F

R23AS 2074-H3A,B, A743 CA-15

R23HCA743-CA40

R23XHCA743-CA40

R24AS 2074-H3C, A743-CA6NM

R25VHCAISI TYPE 440C

R26AISI TYPE 431

R26HCQC Special Alloy

R27AS 2074-H7B, A447-CB7Cu 2

R28AS 2074-H7A, A447-CB7Cu 1

R29-1AA744-CD4MCu, A890-1A

R29-4AA890-4A

R29-5AA890-5A

R30AS 2074-H5C, A351-CF8C

R31AS 2074-H5A, A351-CF8

R31LCA351-CF3

R32AS 2074-H5AM,BM, A743-CF16F

R33AS 2074-H6B, A351-CF8M

R33AS 2074-H6B, A351-CF8M

R33LCA351-CF3M

R33NbAS 2074-H6C

R34AS 2074-H6A, A351-CG8M

R36AS 2074-H9A, A744-CN7M

R37A744-CN7MS

R39A494-CW6M, INCOLOY C-276

R40A494-CW12MW, INCOLOY C-276

R42A494-N7M, HASTELLOY B-2

R43QC Alloy

R47A494-M35-1, MONEL 400

R48A494-CZ100, NICKEL 200




AUSTENITIC STAINLESS STEELS

Austenitic stainless steels are very tough and essentially non-magnetic alloys that are alloyed to produce resistance to corrosion in a variety of environments.

The basic 18% chromium/10% nickel grade (R31) has a very good corrosion resistance in many applications. This alloy can be refined (R31LC) or alloyed with molybdenum (R33,R34) for enhanced corrosion resistance or modified for improved welding (R30) and machining (R32) characteristics. Increasing nickel content and alloying with molybdenum and copper results in greatly improved corrosion resistance in more aggressive environments such as hot sulphuric acid (R36,R37).




AUSTENITIC STAINLESS GRADES

R30AS 2074-H5C, A351-CF8C

R31AS 2074-H5A, A351-CF8

R31LCA351-CF3

R32AS 2074-H5AM,BM, A743-CF16F

R33AS 2074-H6B, A351-CF8M

R33AS 2074-H6B, A351-CF8M

R33LCA351-CF3M

R33NbAS 2074-H6C

R34AS 2074-H6A, A351-CG8M

R36AS 2074-H9A, A744-CN7M

R37A744-CN7MS




DUPLEX STAINLESS STEELS

Duplex stainless steels comprise a mixture of ferrite and austenite, producing a alloy with many of the advantages offered by both structures. They generally have comparable or better corrosion resistance to austenitic steels, with more than twice the yield strength, and are especially resistant to pitting corrosion and stress corrosion cracking in chloride environments.

Duplex stainless steels have for years been providing excellent service in seawater on offshore platforms and in a wide variety of other chloride containing environments.

The pitting resistance equivalent number (PREN) is an empirical guide to the grading of alloys for resistance to seawater. Duplex stainless steel has been designed to exceed the commonly specified PREN of 40 and provide, for example, castings suitable for pumps and valves on offshore oil and gas platforms.




DUPLEX GRADES

R29-1AA744-CD4MCu, A890-1A

R29-4AA890-4A

R29-5AA890-5A




Fatigue Characteristics: These alloys have superior resistance to fatigue and corrosion fatigue.

Machine and Weldability: Duplex and Super Duplex alloys are readily machined. Surface work hardening can occur. These alloys are also readily weldable.




Standards:

Casting specifications UNS J93404, J92205 and J93370/73

ASTM A890 Grades 1A, 1C, 4A, and 5A

Listed in MRO175 for sour service.




Applications:

Duplex and Super Duplex are a high-tech alloys for use in many situations where safer more cost effective, high strength, corrosion resistant alloys are needed. Some of the various applications are:

Worldwide use on offshore development.

Marine environments.

Seawater systems and cooling.

Oil and gas industry.

Process systems in Chemical plants.

Refineries and Petrochemical plants.

Fire water systems.

Pump and valve castings.

DaviesBaird would welcome the opportunity of having our experienced team of foundry engineers and metallurgists work with you to provide the most suitable grade for your application.




MARTENSITIC STAINLESS STEELS

A protective passive oxide film can develop on steels with chromium contents above 12%, imparting to these steels “stainless” characteristics. By maintaining a suitable composition balance between carbon and chromium, a series of high strength stainless steels are produced (R23-R23XHC).

Components cast in these alloys meet specific hardness and wear resistance criteria through closely controlled heat treatment practices. Alloy toughness and versatility are enhanced by additions of nickel and molybdenum (R24).




MARTENSITIC GRADES

R23AS 2074-H3A,B, A743 CA-15

R23HCA743-CA40

R23XHCA743-CA40

R24AS 2074-H3C, A743-CA6NM

R25VHCAISI TYPE 440C




PRECIPITATION HARDENING

Strength and corrosion resistance superior to many martensitic stainless steel alloys is achieved by precipitation hardening a low carbon martensitic or semi-martensitic stainless steel. This is accomplished by accurate alloying and a low temperature heat treatment, allowing machined parts to be age hardened with only minimal distortion and scaling. Depending upon the particular alloy composition and heat treatment programme, precipitation hardening stainless steels can be supplied with appropriate hardness differentials to avoid galling and seizing during metal to metal contact




PRECIPITATION HARDENING GRADES

R27AS 2074-H7B, A447-CB7Cu 2

R28AS 2074-H7A, A447-CB7Cu 1