quality naval dismantlement sheet

[meccanicamg]

Good morning, everyone.
I have the following question to ask you about the naval dismantlement plates that are sometimes bought by the carpenters of heavy metal structures and bases, at prices below the commercial plates and above all with poor mechanical characteristics.

I would like to understand why and if it is true that the plates recovered from naval dismantlement have or can have:
- strange thicknesses other than the usual used in traditional metal carpentry (thickness 22 - 23 - 27 mm versus 20-25-30 mm)
- non-uniform mechanical characteristics (strong internal tensions and non-homogeneous mechanical characteristics such as breaking load and jominy test)
- mechanical characteristics lower than standard

if all this or partially is true, I would like to understand with you if:
- after welding of carpenters make a replenishment of tension could improve at least non-uniformity of tension
- more (you tell me...)

Thank you.

 

[gil]

Hi.
in construction as well as as armor, as well as as beams the pillars, it is used iron of unfair quality to other sectors.

I'm not an expert on the subject, but once I was in a foundry that bought cars from the vans and after having removed other materials, melt the frame to make them swallows. a feb44k armor steel, has resistance around 540n/mmq.
a steel for profiles, such as the classic s235 has 235n/mmq resistance.

It is clear that we pass through a new fusion and therefore there is no problem on the profiles of the material, and any disomogenities. It's like she merges raw material.

the direct use of the recovered material instead I do not think it is possible. Building standards ntc08 clearly stipulates that steel for structural use must have specific certificates. if the material is recovered from a ship of 30 years ago, clearly these certificates can not be there and however would not be well.

you could go for an analysis of the individual pieces in the lab, but the analyses cost a lot, so it is not an economically sustainable option. At most, that steel can be used to make counterweights, or railings or inferriate, in short, structures without structural value.

but with a 25mm dish, I don't think you can do a gate.:tongue:

 

[SHIREN]

Hi hunting---
my experience
a moment the one in 10029
there are tolerances in n° 4 classes that in turn divide into lowew and upper
there may be differences in thickness from -1.4 to 2.2 mm
if in the ship you find sheet 22 maybe it was sold for 20 mm and so on
Thank you very much

 

[meccanicamg]

Hi hunting---
my experience
a moment the one in 10029
there are tolerances in n° 4 classes that in turn divide into lowew and upper
there may be differences in thickness from -1.4 to 2.2 mm
if in the ship you find sheet 22 maybe it was sold for 20 mm and so on
Thank you very much

Thanks shiren, but then why for normal carpenters instead the 20 plate is really almost all from 20 mm +/- 0.5? in the ship abound for safety? Is it a sector so that it might need higher tolerances if it isn't less?

 

[SHIREN]

Thanks shiren, but then why for normal carpenters instead the 20 plate is really almost all from 20 mm +/- 0.5? in the ship abound for safety? Is it a sector so that it might need higher tolerances if it isn't less?

Hello meccanic......
what I indicated are train sheets

while the others are
"planned" sheets in carbon steel

are two very different products and with different costs
Thank you very much

 

[meccanicamg]

Hello meccanic......
what I indicated are train sheets

while the others are
"planned" sheets in carbon steel

are two very different products and with different costs
Thank you very much

I'm clearing the world... So...

If I wanted to check if the pincopallino carpenter is screwing me I could do measurements on the thicknesses to understand what he used or do I have to do chemical analysis of the material? We take into account that destructive tests are not contemplated for the type of carpentry construction except for the removal of a disc of 30 mm in diameter and more.

 

[SHIREN]

I'm clearing the world... So...

If I wanted to check if the pincopallino carpenter is screwing me I could do measurements on the thicknesses to understand what he used or do I have to do chemical analysis of the material? We take into account that destructive tests are not contemplated for the type of carpentry construction except for the removal of a disc of 30 mm in diameter and more.

then
always according to my experience

the train sheets visually are very rough
have the edges on the width ending to (3) (in the sez.)
that is given by the crushing of the drawing
the final headboards on the length are irregular and end roughly to (s) you can also have 100-150 mm blur
if they have an accompanying tag the quality is indicated with (00) double zero

mechanical processing sheet always have a recognition card (paying)
which indicates quality origin n° of melting site etc etc.
visually are standardized with net edges

can also happen that you do a chemical analysis of a train sheet and could be higher than one (mechanical sheet)

several times I happened to find areas where widia carbides were affixed

Thank you very much

 

[meccanicamg]

then
always according to my experience

the train sheets visually are very rough
have the edges on the width ending to (3) (in the sez.)
that is given by the crushing of the drawing
the final headboards on the length are irregular and end roughly to (s) you can also have 100-150 mm blur
if they have an accompanying tag the quality is indicated with (00) double zero

mechanical processing sheet always have a recognition card (paying)
which indicates quality origin n° of melting site etc etc.
visually are standardized with net edges

can also happen that you do a chemical analysis of a train sheet and could be higher than one (mechanical sheet)

several times I happened to find areas where widia carbides were affixed

Thank you very much

if I can try to control during the manufacturing process, otherwise I will have to control everything by finished operation and possibly contest the work of carpentry or carry out tests of effort and analysis of various nature in order to refute any possible constructive minkiata practice.

thanks for your precious info

 

[SHIREN]

if I can try to control during the manufacturing process, otherwise I will have to control everything by finished operation and possibly contest the work of carpentry or carry out tests of effort and analysis of various nature in order to refute any possible constructive minkiata practice.

thanks for your precious info

you would have a huge additional cost
you have to give the documentation of the used materials
from the supplier or the legal representative
where you are excluded from any liability on the supply of raw materials
thank you

 

[cacciatorino]

Thank you for opening this discussion. So far I always realized that the train plates were used to make the rotary material, so I wondered what the ships had to do. :tongue:

At least now I've realized that it's train sheets. di laminazione.....

 

[SHIREN]

Thank you for opening this discussion. So far I always realized that the train plates were used to make the rotary material, so I wondered what the ships had to do. :tongue:

At least now I've realized that it's train sheets. di laminazione.....

:36_1_11:

Hi hunting--
we are in the ship
we wait for our expert:36_1_13:

 

[stefanobruno]

:36_1_11:

Hi hunting--
we are in the ship
we wait for our expert:36_1_13:

is making the model of a panettone.:36_1_1:

 

[Exatem]

Good morning, everyone.
I have the following question to ask you about the naval dismantlement plates that are sometimes bought by the carpenters of heavy metal structures and bases, at prices below the commercial plates and above all with poor mechanical characteristics.

I would like to understand why and if it is true that the plates recovered from naval dismantlement have or can have:
- strange thicknesses other than the usual used in traditional metal carpentry (thickness 22 - 23 - 27 mm versus 20-25-30 mm)
- non-uniform mechanical characteristics (strong internal tensions and non-homogeneous mechanical characteristics such as breaking load and jominy test)
- mechanical characteristics lower than standard

if all this or partially is true, I would like to understand with you if:
- after welding of carpenters make a replenishment of tension could improve at least non-uniformity of tension
- more (you tell me...)

Thank you.

:36_1_11:

Hi hunting--
we are in the ship
we wait for our expert:36_1_13:

is making the model of a panettone.:36_1_1:

that these last two posts are related to me?
I ate it anyway. The model... one is finished and one is under construction and if you want I will post the photos.

I would point out that for about 18 years I was mainly interested in demolitions.
all the iron that was obtained, as well as the other metals, from the demolition came, in our case, sent to a Brescia foundry so I do not think that the plates were resold as used-reusable material. on the fact that the thicknesses are different from what used in carpentry you can make different assumptions.
If it comes to the bandage of the living work, the sheets are subject to a continuous wear that reduces the thickness as much as when the same is reduced by 20-30% compared to what is indicated on the development, the sheet must be replaced. It's a measurement that you do almost every time a ship enters the basin and fades. it can be said that during the life of a hull, almost all the plates, or much of them, is destined to be replaced.
Secondly, if it is a construction of several thousand tons, it is not impossible that the yard has requested a supply of "ad hoc" sheets. on a development of a few hundred square meters, saving one or two mm of "useless" thickness allows a substantial economic advantage both in terms of purchase of the material, and of future consumption.
In any case, when a ship goes to demolition, except in sad cases like that of the concord, it has passed a few tens of years from its varo for which, as you have already been suggested, it is not difficult that in the meantime the norms on the characteristics have changed.

 

[cacciatorino]

Maybe those strange thicknesses are also derived from old inch measurements.

 

[Exatem]

Maybe those strange thicknesses are also derived from old inch measurements.

in fact you can make different hypotheses.
Now by memory I do not remember the thicknesses of some units on which I work usually but when I return to the office I go to take a look. I'm sorry.

 

[meccanicamg]

Thanks, guys. when it comes to ship you are really unsurpassed. It's a topic that's made me perplexed for a few years. there are many anecdotes and tales of successes and damaged carpenters. carpenters that cost 30% less than in addition to packaging the market of serious and honest professionals make harmful and dangerous scams.

 

[SHIREN]

Thanks, guys. when it comes to ship you are really unsurpassed. It's a topic that's made me perplexed for a few years. there are many anecdotes and tales of successes and damaged carpenters. carpenters that cost 30% less than in addition to packaging the market of serious and honest professionals make harmful and dangerous scams.

Hello meccan.........
Maybe I have a few years more than you
from post-war until the end of the 1980s
in my area there was an open-air market in the poggioreal area of huge dimensions called dig
current management center
all that was dismantled by warships or merchants or sunk seeds was recycled (and a big term) in that market
from the island of ponza to all the Tyrrhenian low
for years who had a workshop a factory or an activity connected to the metalworking industry
He was supplying himself in the ditch
and I guarantee that they come from all over Italy
you know how many packages counterfeit and counterfeit the category has elastred
but the thing and the skemata still find some tube high pressure
Thank you very much

 

[Exatem]

Thanks, guys. when it comes to ship you are really unsurpassed. It's a topic that's made me perplexed for a few years. there are many anecdotes and tales of successes and damaged carpenters. carpenters that cost 30% less than in addition to packaging the market of serious and honest professionals make harmful and dangerous scams.

I want you to deepen your statements. What do you mean by "damaging and dangerous scams"? "damaged shoes"?

Hello meccan.........
Maybe I have a few years more than you
from post-war until the end of the 1980s
in my area there was an open-air market in the poggioreal area of huge dimensions called dig
current management center
all that was dismantled by warships or merchants or sunk seeds was recycled (and a big term) in that market
from the island of ponza to all the Tyrrhenian low
for years who had a workshop a factory or an activity connected to the metalworking industry
He was supplying himself in the ditch
and I guarantee that they come from all over Italy
you know how many packages counterfeit and counterfeit the category has elastred
but the thing and the skemata still find some tube high pressure
Thank you very much

wherever demolition sites have been established (always in the naval field) have flourished markets of the used or hypermarkets of recycling. even from us, when in the immediate post-war period they flourished demolition yards now disappeared, it was possible to buy furniture, furniture, etc. etc. from ships in demolition. but today the times have changed and since the year of the entry into force of the law the scraps are classified waste. this has substantially changed the way the scraps have to and can be treated.
I try to explain briefly how we must behave.
a ship is released and goes into disarmament. the first step is its cancellation from the picture of the ship therefore, a commission declares its alienability. a report quantifies the materials on board and is evaluated if part of it can be reusable. If so, the same is landed. the wreck is quantified indicating the quantities of the various materials on board.
steel tot, x bronze, x aluminum, etc., including a certain amount not recoverable and to start to landfill. of the individual materials is defined the scrap value by obtaining the evaluation from the Milan Chamber of Commerce and is estimated the value "at scrap" of the ship. the amount obtained must be deducted the cost of the costs of demolition, the disposal of waste (think about possible asbestos, inspiring liquids), of transport, etc. is obtained thus a net value of the wreck that becomes the base of auction for a sale to the rise.
the buyer enters possession of the wreck but for compliance with the contract is obliged to demolition. therefore are produced documents that quantify every refusal (rottame) to start recovery or disposal.
the foundry that receives the material, weighs it and certifies the introduction in the company, so the circle closes.
This is the rule.. .
Then the mistrust exists, it is undeniable, but I do not think that mechanicalmg refers to material of illicit origin.

 

[meccanicamg]

I want you to deepen your statements. What do you mean by "damaging and dangerous scams"? "damaged shoes"?

Then the mistrust exists, it is undeniable, but I do not think that mechanicalmg refers to material of illicit origin.

exact, I do not refer to illicit material but simply the use of naval decommissioning recovery plates used as if nothing were to build industrial machine bases despite not conforming to the material indicated on the cart.

therefore the incorrect behavior is that of the carpenter who should inform the client of the thing. then if together the client does not ask the certificates to the carpenter worse than worse.

the problems encountered are:
- if the plates were to be 20 mm and I made them with the 23 mm they make me pay 1,20€/kg a lot of kg for nothing, so cheap damage that amplifies when I send in ricottura etc.
- if the plates put them thinner or the carpenters are not covered and stretched there are crazy tensions and carpenters when the mills board as bananas. non uniformity of surface hardness therefore different resistance and abnormal wear inserts for removal of truciole

 

[Exatem]

exact, I do not refer to illicit material but simply the use of naval decommissioning recovery plates used as if nothing were to build industrial machine bases despite not conforming to the material indicated on the cart.

therefore the incorrect behavior is that of the carpenter who should inform the client of the thing. then if together the client does not ask the certificates to the carpenter worse than worse.

the problems encountered are:
- if the plates were to be 20 mm and I made them with the 23 mm they make me pay 1,20€/kg a lot of kg for nothing, so cheap damage that amplifies when I send in ricottura etc.
- if the plates put them thinner or the carpenters are not covered and stretched there are crazy tensions and carpenters when the mills board as bananas. non uniformity of surface hardness therefore different resistance and abnormal wear inserts for removal of truciole

ok, so the problem is not "naval" but it is the most or less correct behavior of the carpenter. . .
the speech we had begun on the particular dimensions of the plates and in particular on the thicknesses. as you said, 3 mm of difference make several euros on a ship from... 4/5000 tons. so there can be that the yard will make custom sheeting.