nhoshi1 Posted July 14, 2015 Share Posted July 14, 2015 I have few steel components (tool steel: E52100) and wanted to get them coated in order to improve their hardness and wear resistance. According to my material provider, company first quenches the steel, then performs tempering at the temperature in the range 185-190oC. The coating company has this process in which the temperature will rise up to 250oC, which is higher than tempering temperature. By heating, I know that the surface hardness will reduce but I am not sure about to what extent? After researching for past few days, I have been very confused as some sources says that the tempered martensite does not loose its properties (change back to austenite) until much higher temperature is reached? (Though the articles I found were mostly about carbon-steel, not alloy/tool steel).Plus, my major confusion is even if heating will make the steel components softer, but I will be applying coating at same temperature which promises increase in value of hardness. So, doesn't it kind of balances it out?It would be of great help if anyone can share his knowledge and help me out.Thanks! Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 14, 2015 Share Posted July 14, 2015 The coating is abrasion/wear resistance rather than hard like a rock compared to putty.Buy it coated fro the manufacturer or have it done professionally.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Bo T Posted July 14, 2015 Share Posted July 14, 2015 Lots of material data sheets on the web. Seems that it will reduce the hardness by 2-3 HRc points. What hardness do you need? What is the hardness of the coating? Quote Link to comment Share on other sites More sharing options...
nhoshi1 Posted July 14, 2015 Author Share Posted July 14, 2015 Current hardness is around 60 HRC and coating has the hardness of 72 HRC. I have also found some of the datasheets on the internet, but they are for first time tempering temperature against hardness (after quenching). In my case, objects are already tempered from the producer and I am heating it again. I could not find any data for this scenario. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 14, 2015 Share Posted July 14, 2015 all the steel cares about is the temperature its baked (tempered again) to get that coating, bake at 250 means its getting a temper cycle at 250, look that up for your alloy Quote Link to comment Share on other sites More sharing options...
Bo T Posted July 14, 2015 Share Posted July 14, 2015 I'm kind of guessing, unless your substrate hardness is critical to the task, your wear resistance should increase as long as the coating is in place. As soon as the coating wears off the wear rate will become faster than the original uncoated piece. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 14, 2015 Share Posted July 14, 2015 I don't believe the OP actually knows what he's asking for. There are so many different ways to apply a hard face suitable to things like bushing guides, etc. Baking on a powder coat, spray or sputter deposition are two more, heck electro plating, sleaving, etc.This is old well established technology, just order it hard faced from the manufacturer. Trying to do it after market is unlikely to be successful seeing as you have no idea how or even what you want beyond specifications. Also doing this after market will void any and all warrantees from the original manufacturer.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
WL smith Posted July 15, 2015 Share Posted July 15, 2015 How hard do you really need it? what is your final use? Quote Link to comment Share on other sites More sharing options...
nhoshi1 Posted July 15, 2015 Author Share Posted July 15, 2015 What I am trying to do is to coat the outer surface of track roller (I have components separated) to improve the wear resistance of surface (as for now, top layer gets pretty wore out after few weeks time). So, for that, I contacted few coating companies to check if they can help. And one of them is giving quite an assurance for better results, but their coating process (PVD) involves rise in temperature up to 250 oC (I am trying Tungsten-Carbide-Cobalt coating). I have already tried DLC but that wasn't a success as DLC wore off too. For now, I am interested in testing only. So, my focus is not to loose any hardness, meaning increase is highly desired (coating can give micro-hardness of 1000Hv) and to improve wear resistance.and my question here is same as I asked earlier: my major confusion is even if heating will make the steel components softer, but at the same temperature, coating will be applied which promises increase in value of hardness. So, doesn't it kind of balances it out?Thank you again. Quote Link to comment Share on other sites More sharing options...
Bo T Posted July 15, 2015 Share Posted July 15, 2015 I believe the coating will decrease the wear rate on your upper surface while it is in place. However, once the coating has worn through the wear rate will increase beyond that of the original rollers. It is impossible to say if it will balance out. You will need to run the coated components through a complete life cycle and then do a detailed analysis. One important question is can the rollers be recoated? Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 15, 2015 Share Posted July 15, 2015 I fear this is a language translation issue, the question was answered and he reposted from not understanding. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 15, 2015 Share Posted July 15, 2015 Once again I get the impression of a mid management guy who has gone over the books and sees how much they spend replacing rollers on the link belt track rigs and believes there's an economical way to cut costs.Without experience in the shop or metallurgy he is simply reading marketing papers and spec sheets and is posting questions based on misunderstanding and a lack of knowledge and experience.It's good to ask questions but asking the dozer manufacturer is the correct venue for information. There isn't a link belt company in the world that isn't trying to maximize the life of high wear parts. Every time one does their sales goes up because it's EXPENSIVE to run heavy equipment.I don't think there's much we can do for the OP, even if we knew exactly how to increase wear resistance he doesn't have the knowledge base to make use of it. It's a good try but isn't going to succeed. I know there's a huge amount of talent and training here but the OP is asking a BLACKSMITHING forum.Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 15, 2015 Share Posted July 15, 2015 honestly I think its the same guy but thanks to IPS 'wonderful' "improvements" we no longer have the tools to look and see Quote Link to comment Share on other sites More sharing options...
patrick Posted August 1, 2015 Share Posted August 1, 2015 The type of coating under discussion here is very thin so there concernce not only about the wear resistance of the coating itself but also of the ability of the base material to support that coating. Since the base material hardness will be reduced by the coating process, its ability to support that coating will be reduced, but I can't say of a couple of HRC points lower hardness will be significant to the applicaiton. The original poster really needs to seek input from a technical representitive of the coating supplier or someone who specializes in tribology. There may be other ways to deal with his problem besides just increasing surface hardness. Quote Link to comment Share on other sites More sharing options...
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