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Different Steels


gazza

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I just put a pic in my gallery of some different types of steel in it there ia a piece of Cold Rolled Steel[CRS]or cold drawn,2 pieces of grade 303 aerospace standard stainless steel and 2 pieces of drillrod.

Notice the different curves/radius the steel makes on the different stock the 10mms CRS bents like most CRS if you keep it moveing quick enough look how the stainless makes a bigger radius because the metal is les prone to heating and work hardens as it bends look also at the radius between the 9mms and 3/8"stainless i have some 10mms stainless which i use for ISOS and it makes a bigger radius again i bet the 3/8" stainless HEX will make an even bigger radius.

Now look at the drillrod the 1085 is oil hardened and the 3/8" is i bet water hardened the oil hardened drillrod bends like stainless lookat the radius were as the 3/8" drillrod bends more like CRS i bet its either because its ater hardened so is cooled faster makeing it more tensile so it bends sharper or its got alot more carbon added to it which again makes it more tensile.

Anyway abit geeky but i thought some of you might be interested in how some of the different metals behave :D

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Oh yeah! That is my kind of post.

I can't believe the drill rods behaved so differently. They both came out of the 1085 oil hardened rack so who knows.

Now, you missed one detail though, how did they stack up in real world bending?

I was asking you about 10mm and I can't believe you already bent it. Isn't it bigger than the 3/8?

Keep em coming!

Tim

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How do they measure up now that would be telling wouldn,t it :tongue

Only kidding i aint like others afraid to share the calibrated results :whistel

Out of those 5 bars in easiest order for me was 1st the 1085 drillrod,2nd the 9mms stainless,3rd the 3/8"drillrod,4th the 10mms crs and 5th the 3/8"stainless.

The 10mms crs was given to me at the same time as the 1085 drillrod from maxwell and was done before christmas after a warm up and plenty of sykeing the 10mms crs went down which hurt the shoulder abit it was not springy like the drillrod and did not ramp up like the stainless i then after a rest got the 1085 drillrod it was the first big drillrod i had tried it was springy but also ramps up like the stainless which is evident by its radiust bend in the photo this bar further injured me at the time i was on top form and hit 2 prs that day one in crs the other in drillrod so i couldnt ask any more of myself.

The 3/8" stainless Hex at 7inches is still the hardest stock i have tried to date the 80ds i feel only stopped me because of a mixture of things length,piont and head to push into,not training or have tried 8inch stock unbraced before and not being at full power.

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That 1085 is some tough steel. A lot of custom knife makers use 1085 because it holds a good edge, it's cheap and mainly because it will hold a good hamon line in the tempering process. Good for custom forged japanese blades- Ever try something high in vanadium like 5160?

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Gazza,

So in any given size of steel the progression would be cold-rolled, then drill rod then stainless? I guess then if someone was working toward a shiny but couldn't quite get it then the 5/16 drill rod might be a good stepping stone.

Can you clarify which stainless is the harder one, the 303 or the 304? Which kind was that stainless 5/16 hex that suprised everyone with it's lower-than-expected calibration numbers? I remember you saying it was a different kind of stainless.

By the way, no wonder that 3/8 stainless ramps up so quick. Looks like it's using up all it's own length with that crazy wide bend!

Last question, we have a steel in this country called stress proof. Have you ever had any experience with that kind of steel? Evidently it's an alloy or something special but I've never been able to obtain any with out costing an arm and a leg for shipping.

Thanks and I really love these technical points you bring out.

Tim

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Tim and Gazza, I hope its ok for me to jump in here. I have found the 303 and 304 to usually be pretty close. They have the same specs. However if one is gonna be a little less I would expect it to be the 304. The 5/16 drill rod is a good stepping stone, but IMO the .323 drill rod is even closer. Lemme know if you want to try a piece. I think I still have some. I had Eric calibrate some 303 5/16 hex and it came out at a expected higher number 645 to be exact. Another option not listed is 12L14 CRS steel. its normally used for machining operations that require a mild steel like cold roll because it machines nicely. However its tensile strength is a bit higher and the 12L14 5/16 Hex I have done definately felt a little harder than the standard FBBC hex. could be my imagination of course. Hope that helps and if you have any questions for me feel free to PM or post.

- Aaron

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Aaron,

With that kinda knowledge jump in all you want my friend.

I know you're a fan of the drill rod from previous posts and I can understand why with the crazy small increments it's available in. Have you had all the various sizes calibrated? Got any other calibration numbers?

Thanks again,

Tim

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Aaron,

With that kinda knowledge jump in all you want my friend.

I know you're a fan of the drill rod from previous posts and I can understand why with the crazy small increments it's available in. Have you had all the various sizes calibrated? Got any other calibration numbers?

Thanks again,

Tim

No Prob Tim, I had about half of the sizes that I have calibrated. I dont have the numbers in front of me because I had to clean out my PM box, so its in a archive file I have to dig thru. sizes I have are: .281, .290, .302, .312, .323, .332, .343, .348, .358, .368. However the numbers alone don't tell the complete story, just like stainless. It is a similiar experience to stainless in that its softer on the kink and the feel of the bend. its springy but never really loads up bad at the end. Instead its pretty much tough to move the whole way thru the bend and never frees up like CRS. very nice workout and challenge steel IMO. I'll get the calibration numbers that I have up as soon as I get a chance.

- Aaron

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Some Stainless Steel grades 303 and 304 information some people might find interesting.

Background

Grade 304 is the standard "18/8" stainless; it is the most versatile and most widely used stainless steel, available in a wider range of products, forms and finishes than any other. It has excellent forming and welding characteristics. The balanced austenitic structure of Grade 304 enables it to be severely deep drawn without intermediate annealing, which has made this grade dominant in the manufacture of drawn stainless parts such as sinks, hollow-ware and saucepans. For these applications it is common to use special "304DDQ" (Deep Drawing Quality) variants. Grade 304 is readily brake or roll formed into a variety of components for applications in the industrial, architectural, and transportation fields. Grade 304 also has outstanding welding characteristics. Post-weld annealing is not required when welding thin sections.

Grade 304L, the low carbon version of 304, does not require post-weld annealing and so is extensively used in heavy gauge components (over about 6mm). Grade 304H with its higher carbon content finds application at elevated temperatures. The austenitic structure also gives these grades excellent toughness, even down to cryogenic temperatures.

Key Properties

These properties are specified for flat rolled product (plate, sheet and coil) in ASTM A240/A240M. Similar but not necessarily identical properties are specified for other products such as pipe and bar in their respective specifications.

Composition

Typical compositional ranges for grade 304 stainless steels are given in table 1.

Table 1. Composition ranges for 304 grade stainless steel

Grade

C

Mn

Si

P

S

Cr

Mo

Ni

N

304

min.

max.

-

0.08

-

2.0

-

0.75

-

0.045

-

0.030

18.0

20.0

-

8.0

10.5

-

0.10

304L

min.

max.

-

0.030

-

2.0

-

0.75

-

0.045

-

0.030

18.0

20.0

-

8.0

12.0

-

0.10

304H

min.

max.

0.04

0.10

-

2.0

-

0.75

-0.045

-

0.030

18.0

20.0

-

8.0

10.5

-

Mechanical Properties

Typical mechanical properties for grade 304 stainless steels are given in table 2.

Table 2. Mechanical properties of 304 grade stainless steel

Grade

Tensile Strength (MPa) min

Yield Strength 0.2% Proof (MPa) min

Elongation (% in 50mm) min

Hardness

Rockwell B (HR B) max

Brinell (HB) max

304

515

205

40

92

201

304L

485

170

40

92

201

304H

515

205

40

92

201

304H also has a requirement for a grain size of ASTM No 7 or coarser.

Physical Properties

Typical physical properties for annealed grade 304 stainless steels are given in table 3.

Table 3. Physical properties of 304 grade stainless steel in the annealed condition

Grade

Density (kg/m3)

Elastic Modulus (GPa)

Mean Coefficient of Thermal Expansion (mm/m/°C)

Thermal Conductivity (W/m.K)

Specific Heat 0-100°C (J/kg.K)

Electrical Resistivity (nW.m)

0-100°C

0-315°C

0-538°C

at 100°C

at 500°C

304/L/H

8000

193

17.2

17.8

18.4

16.2

21.5

500

720

Grade Specification Comparison

Approximate grade comparisons for 304 stainless steels are given in table 4.

Table 4. Grade specifications for 304 grade stainless steel

Grade

UNS No

Old British

Euronorm

Swedish SS

Japanese JIS

BS

En

No

Name

304

S30400

304S31

58E

1.4301

X5CrNi18-10

2332

SUS 304

304L

S30403

304S11

-

1.4306

X2CrNi19-11

2352

SUS 304L

304H

S30409

304S51

-

1.4948

X6CrNi18-11

-

-

These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted.

Possible Alternative Grades

Possible alternative grades to grade 304 stainless steels are given in table 5.

Table 5. Possible alternative grades to 304 grade stainless steel

Grade

Why it might be chosen instead of 304

301L

A higher work hardening rate grade is required for certain roll formed or stretch formed components.

302HQ

Lower work hardening rate is needed for cold forging of screws, bolts and rivets.

303

Higher machinability needed, and the lower corrosion resistance, formability and weldability are acceptable.

316

Higher resistance to pitting and crevice corrosion is required, in chloride environments

321

Better resistance to temperatures of around 600-900°C is needed…321 has higher hot strength.

3CR12

A lower cost is required, and the reduced corrosion resistance and resulting discolouration are acceptable.

430

A lower cost is required, and the reduced corrosion resistance and fabrication characteristics are acceptable.

Corrosion Resistance

Excellent in a wide range of atmospheric environments and many corrosive media. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60°C. Considered resistant to potable water with up to about 200mg/L chlorides at ambient temperatures, reducing to about 150mg/L at 60°C.

Heat Resistance

Good oxidation resistance in intermittent service to 870°C and in continuous service to 925°C. Continuous use of 304 in the 425-860°C range is not recommended if subsequent aqueous corrosion resistance is important. Grade 304L is more resistant to carbide precipitation and can be heated into the above temperature range.

Grade 304H has higher strength at elevated temperatures so is often used for structural and pressure-containing applications at temperatures above about 500°C and up to about 800°C. 304H will become sensitised in the temperature range of 425-860°C; this is not a problem for high temperature applications, but will result in reduced aqueous corrosion resistance.

Heat Treatment

Solution Treatment (Annealing) - Heat to 1010-1120°C and cool rapidly. These grades cannot be hardened by thermal treatment.

Welding

Excellent weldability by all standard fusion methods, both with and without filler metals. AS 1554.6 pre-qualifies welding of 304 with Grade 308 and 304L with 308L rods or electrodes (and with their high silicon equivalents). Heavy welded sections in Grade 304 may require post-weld annealing for maximum corrosion resistance. This is not required for Grade 304L. Grade 321 may also be used as an alternative to 304 if heavy section welding is required and post-weld heat treatment is not possible.

Machining

A "Ugima" improved machinability version of grade 304 is available in bar products. "Ugima" machines significantly better than standard 304 or 304L, giving higher machining rates and lower tool wear in many operations.

Dual Certification

It is common for 304 and 304L to be stocked in "Dual Certified" form, particularly in plate and pipe. These items have chemical and mechanical properties complying with both 304 and 304L specifications. Such dual certified product does not meet 304H specifications and may be unacceptable for high temperature applications.

Applications

Typical applications include:

· Food processing equipment, particularly in beer brewing, milk processing & wine making.

· Kitchen benches, sinks, troughs, equipment and appliances

· Architectural panelling, railings & trim

· Chemical containers, including for transport

· Heat Exchangers

· Woven or welded screens for mining, quarrying & water filtration

· Threaded fasteners

· Springs

Background

Grade 303 represents the optimum in machinability among the austenitic stainless steels. It is primarily used when production involves extensive machining in automatic screw machines. Machinability Rating (compared to B1212) is approximately 78%.

303 is also available as a "Ugima" Improved Machinability grade, with machinability even higher than that of the standard 303.

The sulphur addition which is responsible for the improved machining and galling characteristics of Grade 303 lowers its corrosion resistance to below that of Grade 304. As for other austenitic grades the structure gives 303 excellent toughness, although the sulphur in 303 reduces its toughness slightly.

Grade 303Se (UNS S30323) has a selenium rather than sulphur addition, improving the hot and cold forming characteristics over those of 303 and providing a smoother machined surface finish. The machinability rate is also slightly reduced. Grade 303Se is not readily available in Australia.

Key Properties

These properties are specified for long product (bar) in ASTM A582. Similar but not necessarily identical properties are specified for other products such as wire and forgings in their respective specifications. Grade 303 is not produced in flat rolled products.

Composition

Typical compositional ranges for grade 303 stainless steels are given in table 1.

Table 1. Composition ranges for 303 grade stainless steel

Grade

C

Mn

Si

P

S

Cr

Mo

Ni

Se

303

min.

max.

-

0.15

-

2.00

-

1.00

-

0.20

0.15

-

17.0

19.0

-

8.0

10.0

-

303Se

min.

max.

-

0.15

-

2.00

-

1.00

-

0.20

0.06

-

17.0

19.0

-

8.0

10.0

0.15

min

Mechanical Properties

Typical mechanical properties for grade 303 stainless steels are given in table 2.

Table 2. Mechanical properties of 303 grade stainless steel

Grade

Tensile Strength (MPa)

Yield Strength 0.2% Proof (MPa)

Elongation (% in 50mm)

Hardness

Rockwell B (HR B)

Brinell (HB)

303

-

-

-

-

262 max

Physical Properties

Typical physical properties for annealed grade 303 stainless steels are given in table 3.

Table 3. Physical properties of 303 grade stainless steel in the annealed condition

Grade

Density (kg/m3)

Elastic Modulus (GPa)

Mean Coefficient of Thermal Expansion (mm/m/°C)

Thermal Conductivity (W/m.K)

Specific Heat 0-100°C (J/kg.K)

Electrical Resistivity (nW.m)

0-100°C

0-315°C

0-538°C

at 100°C

at 500°C

303

8027

193

17.3

17.8

18.4

16.3

21.5

500

720

Grade Specification Comparison

Approximate grade comparisons for 303 stainless steels are given in table 4.

Table 4. Grade specifications for 303 grade stainless steel

Grade

UNS No

Old British

Euronorm

Swedish SS

Japanese JIS

BS

En

No

Name

303

S30300

303S31

58M

1.4305

X8CrNiS18-9

2346

SUS 303

303Se

S30323

303S42

-

-

-

-

SUS 303Se

These comparisons are approximate only. The list is intended as a comparison of functionally similar materials not as a schedule of contractual equivalents. If exact equivalents are needed original specifications must be consulted.

Possible Alternative Grades

Possible alternative grades to grade 303 stainless steels are given in table 5.

Table 5. Possible alternative grades to 303 grade stainless steel

Grade

Why it might be chosen instead of 303

304

Better corrosion resistance, formability or weldability are needed, at the expense of lower machinability.

316

Higher resistance to pitting and crevice corrosion is required, in chloride environments. A lower machinability can be accepted.

416

Even higher machinability than 303 is needed, and a lower corrosion resistance can be tolerated.

Or hardening by thermal treatment is required, while maintaining a high machinability.

Corrosion Resistance

Good resistance to mildly corrosive atmospheres, but significantly less than Grade 304 due to the sulphur addition; the sulphide inclusions act as pit initiation sites. Grade 303 should not be exposed to marine or other similar environments, as these will result in rapid pitting corrosion. Because the sulphide inclusions in 303 are primarily aligned along the rolling direction the corrosion resistance is particularly reduced in cross-sections.

Grade 303, like other common austenitic stainless steels, is subject to stress corrosion cracking in chloride containing environments above about 60°C.

Heat Resistance

Good oxidation resistance in intermittent service to 760°C and in continuous service to 870°C. Continuous use in 425-860°C range not usually recommended due to carbide precipitation - 303 usually does not have a low carbon content so is susceptible to sensitisation.

Fabrication

As well as reducing the corrosion resistance, the sulphur additions in 303 also result in poor weldability and reduced formability compared to Grade 304. Sharp bends should not be attempted in 303. A practical compromise alternative may be a 304 Ugima Improved Machinability grade - this does not machine as readily as 303, but does offer better formability (as well as better weldability and corrosion resistance).

Heat Treatment

Solution Treatment (Annealing) - Heat to 1010-1120°C and cool rapidly. This grade cannot be hardened by thermal treatment.

Welding

Not generally recommended but, if unavoidable and a lower strength can be tolerated, use Grade 308L or 309 electrodes. AS 1554.6 does not pre-qualify welding of 303. Welds must be annealed for maximum corrosion resistance.

Machining

A "Ugima" improved machinability version of grade 303 is available in round bar products. This machines significantly better even than standard 303, giving very high machining rates and lower tool wear in many operations.

Applications

Typical applications include:

· Nuts and Bolts

· Bushings

· Shafts

· Aircraft Fittings

· Electrical Switchgear Components

· Gears

· In general any component that is heavily machined and where the corrosion resistance and fabrication properties of 303 are viable.

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Aaron

I personally find the 304 softer/easier than the 303 the stuff i get anyway i think its slightly softer but theres not much in it is because its used more for machining and there are other metals added into the 303 and 304 to make them slightly different i have only got 304 grade twice and both times it was easier than the 303 the hex eric tested was 304 and came out alot weeker poundage wise than yours.

It still proves that regardless of the tolerances and metal used it needs to be batch tested as it all varies.

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:D Post 9 must be the longest post in Gripboard history,top stuff Gary very interesting read!
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