Materials of construction - Revision history

Hassanali at 05:58, 22 February 2016

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	Titanium is growing in use in the chemical industry due to its resistance to seawater corrosion and chlorine cracking. It isn't as strong as stainless steel for holding loads but it can withstand more strain which may be of use in liquid oxidation processes. Its thermal conductivity properties make it a good replacement for cupronickel (Towler et al., 2013).		Titanium is growing in use in the chemical industry due to its resistance to seawater corrosion and chlorine cracking. It isn't as strong as stainless steel for holding loads but it can withstand more strain which may be of use in liquid oxidation processes. Its thermal conductivity properties make it a good replacement for cupronickel (Towler et al., 2013).

	~~[[File:titanium.steel.jpg\|frame\|center\|border\|'''Figure 5:'''Comparison of titanium and stainless steel brackets stress strain curves (Source: The European Journal of Orthodontics)]]~~

	==Plastics==		==Plastics==

Hassanali at 05:57, 22 February 2016

2016-02-22T05:57:18Z

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	Carbon steel and stainless steels are some of the most common metals used in construction. Carbon steel is an alloy between carbon and iron. Also known as mild steel, carbon steel is one of the most commonly used engineering materials. It is favored because it is relatively cheap and widely available. It also has good tensile strength and ductility. However, carbon steel is not generally resistant to corrosion which can be an issue in many environments. When corrosion is expected, stainless steel is often favored. Stainless steel, especially with higher levels of chromium, is more resistant to corrosion (Towler et al., 2013). Stainless steel is also a better choice for low temperatures, as it has a minimum rating of -425 F, as opposed to the minimum rating of carbon steel of -50 F. Stainless steels are also a better choice than carbon steel when temperatures above 1000 F are expected (Biegler et al., 1997)		Carbon steel and stainless steels are some of the most common metals used in construction. Carbon steel is an alloy between carbon and iron. Also known as mild steel, carbon steel is one of the most commonly used engineering materials. It is favored because it is relatively cheap and widely available. It also has good tensile strength and ductility. However, carbon steel is not generally resistant to corrosion which can be an issue in many environments. When corrosion is expected, stainless steel is often favored. Stainless steel, especially with higher levels of chromium, is more resistant to corrosion (Towler et al., 2013). Stainless steel is also a better choice for low temperatures, as it has a minimum rating of -425 F, as opposed to the minimum rating of carbon steel of -50 F. Stainless steels are also a better choice than carbon steel when temperatures above 1000 F are expected (Biegler et al., 1997)

	Other options include nickel and alloys, including Monel, a nickel-copper alloy (Ulrich, 1984). These are also corrosion-resistant to sulfuric and hydrochloric acids and salt water. Nickel-chromium alloys are good to chemical resistance at high temperatures (Turton et al., 2012). Copper and alloys have the advantage of corrosion resistance and good thermal conductivity. Thus, copper is often favored for heat transfer equipment (Ulrich, 1984). Aluminum and its alloys are more moderately priced than copper metals, are lightweight, and are better for low temperatures than carbon steel, however, they have lower strength ~~and can also be susceptible to corrosion~~ (Ulrich, 1984~~). Aluminum is often appropriate for cryogenic operations (Turton et al., 2012~~).		Other options include nickel and alloys, including Monel, a nickel-copper alloy (Ulrich, 1984). These are also corrosion-resistant to sulfuric and hydrochloric acids and salt water. Nickel-chromium alloys are good to chemical resistance at high temperatures (Turton et al., 2012). Copper and alloys have the advantage of corrosion resistance and good thermal conductivity. Thus, copper is often favored for heat transfer equipment (Ulrich, 1984). Aluminum and its alloys are more moderately priced than copper metals, are lightweight, and are better for low temperatures than carbon steel, however, they have lower strength (Ulrich, 1984).
	<center>		<center>
	{\| class="wikitable"		{\| class="wikitable"
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	===Aluminum Alloys and Titanium===		===Aluminum Alloys and Titanium===
	Pure aluminum is highly resistant to corrosion, more so than its alloys. However it lacks mechanical strength which is why pure aluminum is rarely used.		Pure aluminum is highly resistant to corrosion, more so than its alloys. It comes from its formation of a thin oxide film, similar to stainless steel. However it lacks mechanical strength which is why pure aluminum is rarely used. The "Duralumin" or "Dural" range of aluminum alloys are most common with small percentages of copper and magnesium (<5%). These alloys are corrosion resistant and strong. They are used in the textile and food industries in places where mild steel may cause contamination (Towler et al., 2013). Aluminum is often appropriate for cryogenic operations (Turton et al., 2012).

			Titanium is growing in use in the chemical industry due to its resistance to seawater corrosion and chlorine cracking. It isn't as strong as stainless steel for holding loads but it can withstand more strain which may be of use in liquid oxidation processes. Its thermal conductivity properties make it a good replacement for cupronickel (Towler et al., 2013).

			[[File:titanium.steel.jpg\|frame\|center\|border\|'''Figure 5:'''Comparison of titanium and stainless steel brackets stress strain curves (Source: The European Journal of Orthodontics)]]

	==Plastics==		==Plastics==

Hassanali at 05:42, 22 February 2016

2016-02-22T05:42:21Z

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	==Example 3==		==Example 3==
	'''Example Problem''':		'''Example Problem''':
	Chemical Corporation X is known for their highly efficient and cost-effective production pathway for producing ethylene. Due to pressures from newer competitors in the market, the research and development team decides to find ways to cut cost . A researcher discovers a new material he names Material Y. Its price per kilogram ~~to produce is~~		Chemical Corporation X (CCX) is known for their highly efficient and cost-effective production pathway for producing ethylene. Due to pressures from newer competitors in the market, the research and development team decides to find ways to cut cost . A researcher discovers a new material he names Material Y. It has a density of 16000 kg/m<sup>3</sup> s cost of production is $2.00/kg. Its maximum allowable stress is 0.14 N/mm<sup>2</sup>, which is the same as the stainless steel grade CCX uses for its now aging storage tanks. Would it be worth it for CCX to use this new Material Y in place of purchasing their usual stainless steel grade material for its storage tanks? The stainless steel is being purchased at $3.30/kg currently and its density is 8000 kg/m<sup>3</sup>.

			Without much more information to go by, one can only make initial cost comparisons. This is what the cost rating equation is useful for. Using the equation below (Towler et al., 2013):

			<center><math> Cost Rating = {c * \rho \over {\sigma_d}} </math> </center>

			Inputing the information from the example results in a cost rating of 188,571 for stainless steel and a cost rating of 228,571 for Material Y. Material Y is roughly 1.2 times as expensive stainless steel when comparing the relative cost ratings despite Material Y's lower price per kilogram. CCX should stick with their current stainless steel grade for their storage tanks.

	=References=		=References=
	Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.		Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.

Hassanali at 05:17, 22 February 2016

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	! Brinell Hardness		! Brinell Hardness
	! Specific Gravity		! Specific Gravity
	! Max Allowable Stress (~~ksi~~)		! Max Allowable Stress (N/mm<sup>2</sup>)
	! Price ($/kg) (2010)		! Price ($/kg) (2010)
	! Relative Cost (2010)		! Relative Cost (2010)
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	\| 100-200		\| 100-200
	\| 7.9		\| 7.9
	\| 12.9		\| 0.02
	\| 0.82		\| 0.82
	\| 1		\| 1
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	\| 160		\| 160
	\| 8.0		\| 8.0
	\| 20		\| 0.14
	\| ~3.31		\| 2.55-3.79
	\| 2.0-3.0		\| 2.0-3.0
	\|-		\|-
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	\| 30-100		\| 30-100
	\| 8.9		\| 8.9
	\| 6.7		\| 0.046
	\| 8.44		\| 8.44
	\| 22.8		\| 22.8
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	\| 80-150		\| 80-150
	\| 8.9		\| 8.9
	\| 10		\| 0.069
	\| 21.74		\| 21.74
	\| 39.2		\| 39.2
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	\| 120-250		\| 120-250
	\| 8.8		\| 8.8
	\| 18.7		\| 0.13
	\| 17.11		\| 17.11
	\| 16.4		\| 16.4
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	\| 150		\| 150
	\| 4.5		\| 4.5
	\| 10		\| 0.069
	\| 7.39		\| 7.39
	\| 6.8		\| 6.8
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	==Example 3==		==Example 3==
	'''Example Problem''':		'''Example Problem''':
	Chemical Corporation X is known for their highly efficient and cost-effective production pathway for producing ethylene. Due to pressures from newer competitors in the market, the research and development team decides to find ways to cut cost . A researcher discovers a new material he names Material Y. Its		Chemical Corporation X is known for their highly efficient and cost-effective production pathway for producing ethylene. Due to pressures from newer competitors in the market, the research and development team decides to find ways to cut cost . A researcher discovers a new material he names Material Y. Its price per kilogram to produce is
	=References=		=References=
	Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.		Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.

Hassanali at 05:06, 22 February 2016

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	! Specific Gravity		! Specific Gravity
	! Max Allowable Stress (ksi)		! Max Allowable Stress (ksi)
	! Relative Cost		! Price ($/kg) (2010)
			! Relative Cost (2010)
	\|-		\|-
	\| Mild (carbon) steel		\| Mild (carbon) steel
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	\| 7.9		\| 7.9
	\| 12.9		\| 12.9
			\| 0.82
	\| 1		\| 1
	\|-		\|-
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	\| 8.0		\| 8.0
	\| 20		\| 20
			\| ~3.31
	\| 2.0-3.0		\| 2.0-3.0
	\|-		\|-
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	\| 8.9		\| 8.9
	\| 6.7		\| 6.7
			\| 8.44
	\| 22.8		\| 22.8
	\|-		\|-
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	\| 8.9		\| 8.9
	\| 10		\| 10
			\| 21.74
	\| 39.2		\| 39.2
	\|-		\|-
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	\| 8.8		\| 8.8
	\| 18.7		\| 18.7
			\| 17.11
	\| 16.4		\| 16.4
	\|-		\|-
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	\| 4.5		\| 4.5
	\| 10		\| 10
			\| 7.39
	\| 6.8		\| 6.8
	\|}		\|}
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	<center><math> Cost Rating = {c * \rho \over {\sigma_d}} </math> </center>		<center><math> Cost Rating = {c * \rho \over {\sigma_d}} </math> </center>

	Where '''c''' is cost per unit mass ($/kg), '''ρ''' is density (kg/m3), and '''σd''' is maximum allowable stress (N/mm2).		Where '''c''' is cost per unit mass ($/kg), '''ρ''' is density (kg/m3), and '''σ<sub>d</sub>''' is maximum allowable stress (N/mm2).

	This rating lets designers find what material will be the cheapest for the requirements needed for the design. More variables can be inserted in the equation depending on the design’s restraints (e.g. maximum temperature rating). As such, the rating is somewhat limited.		This rating lets designers find what material will be the cheapest for the requirements needed for the design. More variables can be inserted in the equation depending on the design’s restraints (e.g. maximum temperature rating). As such, the rating is somewhat limited.
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	==Example 1==		==Example 1==
			'''Example Problem''':
	Chlorobenzene is produced by reacting liquid benzene with gaseous chlorine. The reaction takes place at 328K and 2.4 bar. If both the feeds are at 293K and atmospheric pressure, what are appropriate materials for the inlet piping and the reactor? (Adapted from ''Chemical Engineering Design'' (Towler et al., 2013)).		Chlorobenzene is produced by reacting liquid benzene with gaseous chlorine. The reaction takes place at 328K and 2.4 bar. If both the feeds are at 293K and atmospheric pressure, what are appropriate materials for the inlet piping and the reactor? (Adapted from ''Chemical Engineering Design'' (Towler et al., 2013)).

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	Hoop stress dominates as it is greater than the calculated longitudinal stress thickness, so the hoop stress added on with the corrosion allowance = 15.3 mm + 4.00 mm = 19.3 mm. Therefore, the wall thickness should be 19.3 mm.		Hoop stress dominates as it is greater than the calculated longitudinal stress thickness, so the hoop stress added on with the corrosion allowance = 15.3 mm + 4.00 mm = 19.3 mm. Therefore, the wall thickness should be 19.3 mm.

			==Example 3==
			'''Example Problem''':
			Chemical Corporation X is known for their highly efficient and cost-effective production pathway for producing ethylene. Due to pressures from newer competitors in the market, the research and development team decides to find ways to cut cost . A researcher discovers a new material he names Material Y. Its
	=References=		=References=
	Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.		Biegler LT, Grossmann IE, Westerberg AW. Systematic Methods of Chemical Process Design. Upper Saddle River: Prentice Hall; 1997.

Hassanali at 04:48, 22 February 2016

2016-02-22T04:48:33Z

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	Copper is a soft metal which is equally easy to work with as Nickel and is found in abundant supply. Its soft nature provides it with good electrical and thermal conductivity. Copper is common in the food industry as well, typically in brewing. Transfer tubes and small-bore pipes often contain copper for its strong heat transfer properties. Copper doesn't react with water but it does slowly react with oxygen in the air. This reaction doesn't produce rust but rather a layer of copper dioxide which protects copper from corrosion. Copper is resistant to caustic alkalis, except ammonia, and many salts and organic acids. Mineral acids are harmful to copper, however (Towler et al., 2013).		Copper is a soft metal which is equally easy to work with as Nickel and is found in abundant supply. Its soft nature provides it with good electrical and thermal conductivity. Copper is common in the food industry as well, typically in brewing. Transfer tubes and small-bore pipes often contain copper for its strong heat transfer properties. Copper doesn't react with water but it does slowly react with oxygen in the air. This reaction doesn't produce rust but rather a layer of copper dioxide which protects copper from corrosion. Copper is resistant to caustic alkalis, except ammonia, and many salts and organic acids. Mineral acids are harmful to copper, however (Towler et al., 2013).

	Copper can form many alloys. The main ones are brasses (alloyed with zinc) and bronzes (alloyed with tin). They are nearly equally corrosion resistant to metals. Their main use is in valves and other small fittings along with pipes (Towler et al., 2013). As temperature goes down, copper alloys become more ductile and even stronger. An alloy with 70% copper that contains nickel and other strengthening elements is called a "cupronickel" alloy. Cupronickels can easily be fabricated due to the complete solubility between copper and nickel. Cupronickels are strong against seawater corrosion and are resistant to macrofouling and thus are often used in marine applications (e.g. seawater desalination plants, offshore oil platforms, etc). Choosing the right alloy depends on what properties one would like most expressed from thermal conductivity to tensile strength.		Copper can form many alloys. The main ones are brasses (alloyed with zinc) and bronzes (alloyed with tin). They are nearly equally corrosion resistant to metals. Their main use is in valves and other small fittings along with pipes (Towler et al., 2013). As temperature goes down, copper alloys become more ductile and even stronger. An alloy with 70% copper that contains nickel and other strengthening elements is called a "cupronickel" alloy. Cupronickels can easily be fabricated due to the complete solubility between copper and nickel. Cupronickels are strong against seawater corrosion and are resistant to macrofouling and thus are often used in marine applications (e.g. seawater desalination plants, offshore oil platforms, etc). Choosing the right alloy depends on what properties one would like most expressed from thermal conductivity to tensile strength (CDAI).

	<center>		<center>
	{\| class="wikitable" style="text-align:center"		{\| class="wikitable" style="text-align:center"
	\|+ '''Table 5:''' Typical Physical Properties of Copper Nickel Alloys (Copper Development Association)		\|+ '''Table 5:''' Typical Physical Properties of Copper Nickel Alloys (Copper Development Association Inc.)
	! Alloy		! Alloy
	!Density<br/>g/cm<sup>3</sup>		!Density<br/>g/cm<sup>3</sup>
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	\|}		\|}
	</center>		</center>

			Monel is a nickel alloy compromised of mostly nickel (~65%) and copper with other strengthening elements like iron. Monel is stronger than pure nickel and is considered a "single-phase alloy" due to the compatibility of nickel and copper. It is the second most commonly used alloy in chemical plants and is right up there with stainless steel in terms of its widespread uses. It also has specific advantages in certain situations when compared with stainless steels, such as when working with dilute mineral acids and working under reducing conditions. Its only big negative is its price when compared with steel (Towler et al., 2013). Monel is very difficult to machine due to work-hardening which makes its production cost increase relative to its material cost (Monel can be up to 10 times more expensive than nickel and copper). Monel is therefore typically used in situations where it has its inherent advantages and where its cost is outweighed by its benefits. Monel is used in many of the same industries as cupronickel alloys, including marine engineering and oil refinery. However, one must be careful not to put monel near steel in seawater due to the potential of galvanic corrosion (Ulrich, 1984).

			===Aluminum Alloys and Titanium===
			Pure aluminum is highly resistant to corrosion, more so than its alloys. However it lacks mechanical strength which is why pure aluminum is rarely used.

	==Plastics==		==Plastics==

Helenwu2: /* Types of Corrosion */

2016-02-22T04:43:08Z

Types of Corrosion

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	Uniform corrosion is the most common type of corrosion and is considered the “general wastage of material,” while disregarding other sources of wear. Due to the nature of this type of corrosion, the corrosion rate can be predicted and experimentally determined. Corrosion testing is done to predict the penetration rate in inches per year, and can be expressed by the following equation,		Uniform corrosion is the most common type of corrosion and is considered the “general wastage of material,” while disregarding other sources of wear. Due to the nature of this type of corrosion, the corrosion rate can be predicted and experimentally determined. Corrosion testing is done to predict the penetration rate in inches per year, and can be expressed by the following equation,
	<br>		<br>
	<center><math>ipy = 12w/tAp</math></center>		<center><math>ipy = {12w \over tAp}</math></center>
	<br>		<br>
	where ''w''=mass loss in time ''t'' (lb), ''t''=time (years), ''A''=surface area (ft<sup>2</sup>), ''p''=density of material (lb/ft<sup>3</sup>). Acceptable corrosion rates for carbon and low alloy steels are given in Table 2. For more expensive materials, these corrosion rates should be cut in half (Towler et al., 2013).		where ''w''=mass loss in time ''t'' (lb), ''t''=time (years), ''A''=surface area (ft<sup>2</sup>), ''p''=density of material (lb/ft<sup>3</sup>). Acceptable corrosion rates for carbon and low alloy steels are given in Table 2. For more expensive materials, these corrosion rates should be cut in half (Towler et al., 2013).

Helenwu2: /* Example 2 */

2016-02-22T04:34:26Z

Example 2

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	<center><math>t = {Pi Di \over {2SE - 1.2Pi}}</math></center>		<center><math>t = {Pi Di \over {2SE - 1.2Pi}}</math></center>

	''Pi'' = internal pressure, ''D'' = internal diameter, ''S'' = maximum allowable stress, ''E'' = welded joint efficiency. In this example, hoop stress is 15.3 mm.		''Pi'' = internal pressure, ''D'' = internal diameter, ''S'' = maximum allowable stress (found in literature tables), ''E'' = welded joint efficiency (based on type of weld). In this example, hoop stress is 15.3 mm.

	Longitudinal stress can be calculated by the equation		Longitudinal stress can be calculated by the equation

Helenwu2: /* Case Study */

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Case Study

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 =Case Study=
 Chlorobenzene is produced by reacting liquid benzene with gaseous chlorine. The reaction takes place at 328K and 2.4 bar. If both the feeds are at 293K and atmospheric pressure, what are appropriate materials for the inlet piping and the reactor? (Adapted from ''Chemical Engineering Design'' (Towler et al., 2013)).
 Both benzene and dry chlorine are not corrosive and therefore, carbon steel can be used as the inlet piping. Note that if the gaseous chlorine is actually wet chlorine, it becomes very corrosive to most metals and a plastic should likely be used. While the reactor is at higher pressure than atmospheric pressure, it is well below the maximum allowable stress for all common materials (Towler et al., 2013). However, a side product of the reactor is HCl which is corrosive. Likely, the HCl concentration will not be high enough to corrode the material but this should be investigated further.  If concentration is >50% either in the reactor or later in the process, another material such as a plastic should be
 =References=

Hassanali at 03:52, 22 February 2016

2016-02-22T03:52:57Z

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	<center>		<center>
	{\| class="wikitable" style="text-align:center"		{\| class="wikitable" style="text-align:center"
	\|+ '''Table 5:''' ~~Commonly Used Grades~~ of ~~Austenitic Stainless Steel~~ (~~Towler et al., 2013~~)		\|+ '''Table 5:''' Typical Physical Properties of Copper Nickel Alloys (Copper Development Association)
	! Alloy		! Alloy
	!Density<br/>g/cm<sup>3</sup>		!Density<br/>g/cm<sup>3</sup>
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	Callister W, Rethwisch D. Materials Science and Engineering. Wiley: New York, 2011.		Callister W, Rethwisch D. Materials Science and Engineering. Wiley: New York, 2011.

			Copper Development Association Inc. Copper.org [Internet]. Physical Properties of Copper Nickel Alloys [2000]. Available from: http://www.copper.org/applications/marine/cuni/properties/physical/

	Engineering Archives Website. Stress Strain Diagram. http://www.engineeringarchives.com/les_mom_stressstraindiagram.html.		Engineering Archives Website. Stress Strain Diagram. http://www.engineeringarchives.com/les_mom_stressstraindiagram.html.

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	Peters MS, Timmerhaus KD. Plant Design and Economics for Chemical Engineers. 5th ed. New York: McGraw Hill; 2003.		Peters MS, Timmerhaus KD. Plant Design and Economics for Chemical Engineers. 5th ed. New York: McGraw Hill; 2003.

			Stainless Steel Industry of America. The Stainless Steel Information Center [Internet]. Relationship between hardness and strength [February 2013]. Available from:
			http://www.ssina.com/overview/history.html

	Towler G, Sinnott R. Chemical Engineering Design: Principles, Practice and Economics of Plant and Process Design. 2nd ed. Boston: Elsevier; 2013.		Towler G, Sinnott R. Chemical Engineering Design: Principles, Practice and Economics of Plant and Process Design. 2nd ed. Boston: Elsevier; 2013.
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	VanAken D. Industrial Heating Website [Internet]. Relationship between hardness and strength [updated 2001 Mar 7; cited 2015 Mar 1]. Available from: http://www.industrialheating.com/articles/84495-engineering-concepts-relationship-between-hardness-and-strength?v=preview.		VanAken D. Industrial Heating Website [Internet]. Relationship between hardness and strength [updated 2001 Mar 7; cited 2015 Mar 1]. Available from: http://www.industrialheating.com/articles/84495-engineering-concepts-relationship-between-hardness-and-strength?v=preview.

	~~Stainless Steel Industry of America. The Stainless Steel Information Center [Internet]. Relationship between hardness and strength [February 2013]. Available from:~~
	~~http://www.ssina.com/overview/history.html~~