1 00:00:01,920 --> 00:00:06,960 Speaker 1: Welcome to Brainstuff production of iHeart Radio, Hey brain Stuff 2 00:00:07,000 --> 00:00:11,760 Speaker 1: Lauren Vogel Bomb Here. From bathroom sinks and kitchen appliances 3 00:00:11,840 --> 00:00:15,080 Speaker 1: to New York's Chrysler building and the St. Louis Gateway arch. 4 00:00:15,560 --> 00:00:18,800 Speaker 1: The world sometimes seems like it's covered in stainless steel, 5 00:00:19,560 --> 00:00:23,440 Speaker 1: and why not. The material is not only sturdy and versatile, 6 00:00:23,640 --> 00:00:27,520 Speaker 1: but also stainless, as the name implies. But is it 7 00:00:27,600 --> 00:00:32,640 Speaker 1: really impossible to stain stainless steel? Stainless steel is a 8 00:00:32,640 --> 00:00:35,560 Speaker 1: family of materials that gets its handle from corrosion and 9 00:00:35,600 --> 00:00:41,159 Speaker 1: oxidation resistant properties that protect it from rust and unsightly blotches. Generally, 10 00:00:41,240 --> 00:00:44,080 Speaker 1: these steels are a mixture of iron and at least 11 00:00:44,120 --> 00:00:47,760 Speaker 1: ten point five percent chromium, sometimes rounded to eleven percent 12 00:00:47,800 --> 00:00:52,720 Speaker 1: by engineers. When exposed to oxygen and moisture. For instance, 13 00:00:52,720 --> 00:00:56,200 Speaker 1: when a stainless steel pan is nicked or dinged, chromium 14 00:00:56,280 --> 00:00:59,720 Speaker 1: is an element that produces thin oxide film that coats 15 00:00:59,760 --> 00:01:04,120 Speaker 1: the product. This self repairing feature of stainless steel ensures 16 00:01:04,160 --> 00:01:08,800 Speaker 1: that the object will always look smooth and shiny. Various 17 00:01:08,800 --> 00:01:12,440 Speaker 1: European and American metallurgists claimed to have invented this wondrous material. 18 00:01:13,440 --> 00:01:16,880 Speaker 1: We do know that Croup Iron Works in Germany created 19 00:01:16,920 --> 00:01:19,720 Speaker 1: an acid resistant steel as early as nineteen o eight, 20 00:01:19,959 --> 00:01:22,479 Speaker 1: which was used for the hull of a yacht. Two 21 00:01:22,480 --> 00:01:26,200 Speaker 1: other German researchers discovered the relationship between chromium content and 22 00:01:26,360 --> 00:01:30,080 Speaker 1: corrosion resistance. That metal containing at least ten point five 23 00:01:30,440 --> 00:01:35,600 Speaker 1: chromium had a greater resistance to corrosion. Meanwhile, American Elwood 24 00:01:35,600 --> 00:01:39,640 Speaker 1: Haynes patented one type of stainless steel precursor in nineteen eleven. 25 00:01:40,080 --> 00:01:43,679 Speaker 1: An English researcher Harry Brearley developed a similar material around 26 00:01:43,680 --> 00:01:47,280 Speaker 1: the same time. After a four year dust up in 27 00:01:47,319 --> 00:01:51,200 Speaker 1: which Haynes successfully opposed Brierly's attempt to patent his version 28 00:01:51,200 --> 00:01:54,400 Speaker 1: of the steel, the two pooled resources to market their 29 00:01:54,400 --> 00:01:58,360 Speaker 1: wares as the American Stainless Steel Company. These and other 30 00:01:58,400 --> 00:02:02,360 Speaker 1: stainless metals found their way to cutlery, airplane parts, golf clubs, 31 00:02:02,400 --> 00:02:07,160 Speaker 1: and other items almost immediately, but not all stainless steel 32 00:02:07,400 --> 00:02:11,519 Speaker 1: is created equal. There are four main types of stainless steel, 33 00:02:11,680 --> 00:02:16,400 Speaker 1: classified by structure and composition. The most common variety is astenatic. 34 00:02:17,720 --> 00:02:21,720 Speaker 1: Of the stainless steel produced falls in this category. Astenetic 35 00:02:21,800 --> 00:02:24,640 Speaker 1: steels can be found in products ranging from cutlery and 36 00:02:24,680 --> 00:02:29,440 Speaker 1: cookware to automotive trim and industrial applications. The material contains 37 00:02:29,480 --> 00:02:32,960 Speaker 1: at least sixteen percent chromium, no more than zero point 38 00:02:33,000 --> 00:02:37,200 Speaker 1: one five percent carbon, and usually includes nickel or manganese 39 00:02:37,240 --> 00:02:42,040 Speaker 1: for added durability. Meanwhile, for Riddic stainless steels contain up 40 00:02:42,040 --> 00:02:45,320 Speaker 1: to twenty seven percent chromium, often as well as aluminum 41 00:02:45,400 --> 00:02:49,079 Speaker 1: or titanium, but if little or no nickel, that means 42 00:02:49,120 --> 00:02:52,639 Speaker 1: that while these materials are highly resistant to corrosion, they're 43 00:02:52,680 --> 00:02:56,639 Speaker 1: less durable than their austenetic cousins. For Ridic steels are 44 00:02:56,720 --> 00:03:00,400 Speaker 1: more affordable than austenetic varieties and are commonly used in flers, 45 00:03:00,480 --> 00:03:05,480 Speaker 1: exhaust systems, kitchen counters, and sinks. Then we have martin 46 00:03:05,600 --> 00:03:08,720 Speaker 1: zitic stainless steels, which are less corrosion resistant than the 47 00:03:08,760 --> 00:03:11,760 Speaker 1: first two types, but are noted for their extreme strength 48 00:03:11,800 --> 00:03:16,480 Speaker 1: and durability, and the material contains twelve to fourteen chromium 49 00:03:16,760 --> 00:03:20,800 Speaker 1: along with small amounts of molybdenum and carbon. These steels 50 00:03:20,840 --> 00:03:23,720 Speaker 1: also contain little to know nickel less than two percent 51 00:03:25,160 --> 00:03:27,919 Speaker 1: Martin's that ex stainless steels are magnetic and are often 52 00:03:28,000 --> 00:03:30,519 Speaker 1: used in products where this feature is useful like a 53 00:03:30,600 --> 00:03:32,920 Speaker 1: kitchen back splash, to which a spice rack or other 54 00:03:32,960 --> 00:03:38,720 Speaker 1: metal object can be attached without using fasteners. Finally, duplex 55 00:03:38,720 --> 00:03:42,000 Speaker 1: stainless steels combine the benefits of austenite and ferrite to 56 00:03:42,120 --> 00:03:46,280 Speaker 1: provide enhanced decay resistance and beefed up strength and durability. 57 00:03:46,520 --> 00:03:49,640 Speaker 1: Metallurgists typically look to create a mix that's half austenitic 58 00:03:49,720 --> 00:03:52,720 Speaker 1: and half fretic. The result is a material that features 59 00:03:52,760 --> 00:03:55,240 Speaker 1: more chromium and less nickel than is found in pure 60 00:03:55,240 --> 00:03:59,760 Speaker 1: austenitic steels, about twenty two to chromium and five percent nickel, 61 00:04:00,200 --> 00:04:03,720 Speaker 1: as well as a high level of molybdenum. These steels 62 00:04:03,720 --> 00:04:08,320 Speaker 1: are primarily used in chemical plants and piping applications. You 63 00:04:08,480 --> 00:04:11,320 Speaker 1: may have noticed our use of the term resistant when 64 00:04:11,320 --> 00:04:15,600 Speaker 1: referring to these stainless steel's capacity for avoiding blemishes. So 65 00:04:15,840 --> 00:04:19,480 Speaker 1: is the material just stain resistant or completely stain proof? 66 00:04:20,920 --> 00:04:24,200 Speaker 1: And despite the hearty protection that it affords users, stainless 67 00:04:24,200 --> 00:04:29,000 Speaker 1: steel is more stain less than stainless. In other words, 68 00:04:29,200 --> 00:04:33,000 Speaker 1: while the material is highly resistant to discoloration, blemishes, and 69 00:04:33,120 --> 00:04:37,400 Speaker 1: other imperfections, it's not completely impenetrable. And just look at 70 00:04:37,440 --> 00:04:39,760 Speaker 1: the Gateway Arch, which is starting to show its age 71 00:04:39,800 --> 00:04:43,080 Speaker 1: with rust and k after five decades of welcoming tourists 72 00:04:43,120 --> 00:04:47,080 Speaker 1: to St. Louis. The protective layer of film covering a 73 00:04:47,160 --> 00:04:50,599 Speaker 1: stainless steel object can break down over time, leading to 74 00:04:50,680 --> 00:04:55,160 Speaker 1: corrosion and pitting. In addition, compounds like chloride, hydrogen and 75 00:04:55,240 --> 00:04:58,599 Speaker 1: hydrogen sulfide often cause the film to stress and crack. 76 00:05:00,080 --> 00:05:02,720 Speaker 1: The level of rest resistance provided by a particular steel 77 00:05:02,839 --> 00:05:06,000 Speaker 1: depends largely on the materials used to create it. The 78 00:05:06,040 --> 00:05:10,479 Speaker 1: more chromium, the more corrosion protection. The sturdier. Stainless steels 79 00:05:10,520 --> 00:05:13,880 Speaker 1: also feature at least eight percent nickel, which provides further 80 00:05:13,960 --> 00:05:19,480 Speaker 1: defense against tarnish. Some products are tagged with numbers indicating 81 00:05:19,480 --> 00:05:23,560 Speaker 1: their proportions of chromium and nickel. For instance, eighteen over 82 00:05:23,640 --> 00:05:26,320 Speaker 1: ten flatwear is sold at a premium because it has 83 00:05:26,360 --> 00:05:30,119 Speaker 1: eighteen percent chromium and ten percent nickel content, providing greater 84 00:05:30,160 --> 00:05:35,160 Speaker 1: protection against corrosion than ordinary flatwear for household users. It's 85 00:05:35,160 --> 00:05:38,680 Speaker 1: important to understand that many metals advertised as stainless steel 86 00:05:38,880 --> 00:05:43,520 Speaker 1: are actually stainless steel plated. The plate is corrosion resistant, 87 00:05:43,640 --> 00:05:46,680 Speaker 1: but is susceptible to damage if cut or scratched deep 88 00:05:46,760 --> 00:05:50,200 Speaker 1: enough to reach the underlying material. Because the plates can 89 00:05:50,240 --> 00:05:53,400 Speaker 1: also wear off over time, buyers should clarify whether a 90 00:05:53,400 --> 00:05:57,239 Speaker 1: particular product is made completely of stainless steel or simply plated. 91 00:05:58,920 --> 00:06:01,880 Speaker 1: Whether plated or not, your stainless steel appliances and other 92 00:06:01,920 --> 00:06:05,080 Speaker 1: products need to be cleaned most of the time. Good 93 00:06:05,080 --> 00:06:07,680 Speaker 1: old fashioned soap and water will do the trick. For 94 00:06:07,800 --> 00:06:11,599 Speaker 1: tougher stains, Professionals recommend a variety of household remedies. A 95 00:06:11,640 --> 00:06:14,279 Speaker 1: couple dabs of olive oil or window cleaner can remove 96 00:06:14,360 --> 00:06:17,599 Speaker 1: most of those pesky fingerprints and smudges, while white or 97 00:06:17,640 --> 00:06:21,520 Speaker 1: cider vinegar will restore shine. And don't use steel wool 98 00:06:21,560 --> 00:06:24,920 Speaker 1: pads or harsh cleaning powders, as they'll scratch the surface. 99 00:06:25,600 --> 00:06:27,440 Speaker 1: If you need to remove burnt on food from a 100 00:06:27,440 --> 00:06:30,320 Speaker 1: stainless steel pan, let it soak in warm water and 101 00:06:30,320 --> 00:06:32,919 Speaker 1: then clean it with baking soda and a gentle nylon 102 00:06:33,080 --> 00:06:41,000 Speaker 1: or plant based scouring pad. Today's episode was written by 103 00:06:41,040 --> 00:06:43,599 Speaker 1: Chris Opfer and produced by Tyler Clang. For more on 104 00:06:43,640 --> 00:06:45,760 Speaker 1: this and lots of other shiny topics, visit how stuff 105 00:06:45,800 --> 00:06:48,400 Speaker 1: works dot com. Brain Stuff is production of i Heeart 106 00:06:48,480 --> 00:06:50,880 Speaker 1: Radio or more podcasts. My heart Radio is at the 107 00:06:50,920 --> 00:06:53,719 Speaker 1: iHeart Radio app, Apple Podcasts, or wherever you listen to 108 00:06:53,760 --> 00:06:54,600 Speaker 1: your favorite shows.