不锈钢知识漫谈(一)
2021-01-29

前言:

Iron and steel is the foundation of the national economy, any industry can not be separated from the application of steel.我们能住在房子里吗, 做饭的工具, 纺织机械, 行走的车辆, 能源设备, 可以替代钢铁的材料?没有.所以,没有钢铁,我们将一无所有.人类活动决定物质世界, human from the understanding of nature to understand themselves, 人类需要什么?男人发现了火, 他学会了工具;人类学会了把房子放在一起以保护它们不受野兽的伤害;把房子放在一起, 了解人类的社会活动;社会活动导致不同的需求, and the development of steel is from people's needs.

钢是怎么炼成的??这是一个非常普遍的问题,却反映了钢铁发展缓慢的漫长历史.钢最早是什么时候发现的,因为没有文字,所以没有记录.We have recorded the processing methods of iron and steel, 只有铸造技术, the casting technology is 5000 years old or 7000 years old, the unearthed relics are constantly changing the age.This technology to the more than 200 years ago the industrial revolution, 炼钢技术, steel from static pressure engineering development for dynamic pressure, 用于各种结构的材料, 当火车, 船, 汽车, 飞机 and aerospace and petrochemical industrial, 特殊钢发展, 不锈钢的性能是在特种钢的基础上发明的.也成为钢铁mg官方电子平台族的一员.

产品结构采用钢结构

1. 钢材品种分类:

2. 钢铁制造方法分类:

1)铸件冶金

铸造是使用热熔金属, 把它变成液体,然后倒进模具里, 固化成型.这就是真理,方可以圆.铸造工艺特点:可生产任意复杂形状, 是其他加工技术无法比拟的.只有几克的环那么小, 有数百吨的架子那么大, 如轧机机架, 液压机站, the most widely used in metal processing technology, 飞机, 船只, 铁路车辆, 汽车, 运输设施、农机、炊具等都离不开铸造技术, roughly accounting for more than 60% of the metal processing.

2)冶金锻造

锻造加工技术是最古老的金属加工技术, 常言道, 彻底的, 硬到钢铁, 这就是锻造的意义.适用于硬变形钢和多合金钢, 多组织凝固形成内部裂纹和缩孔. 通过锻造, the internal cracks and shrinkage holes are extruded, 从而消除内部裂纹和缩孔,提高钢基体的密实度.Especially for large size and large castable materials, 内中心凝固时间较长,形成缩孔.例如, 大型电机轴, 卷, 传动轴等通过锻造加工工艺可以满足技术要求.

3)轧光冶金

Calendering technology is often said to 卷 plastic deformation.锻造技术是随着工业革命而发展起来的实用技术, 而锻件加工向节能化、符合现代要求的方向发展是其主要的加工技术.The main production of long and thin metal products, 连续轧制块坯成板材, 酒吧和管, and then extended 卷ing profiles of different sections (Angle steel, 槽钢, 工字梁的钢, 方钢, 扁钢和棒材, 等.)

4)磨削冶金

Metal powder is a common product for daily use.Used in mould (carbide: seamless steel tube piercing die, 钢模具图纸, 加工刀具, 石油钻), 磁性材料, 铁素体, 永久磁铁, 等.), 过滤器(分子过滤器, 钢液过滤,), 催化剂(聚合物分解, 化学, 石油裂解), 电池和涂料.特别是电器用多孔无油合金轴承(风机轴承), 空调, 冰箱, 等.).Metal powder manufacturing technology has mechanical crushing method, embrittlement treatment + mechanical crushing method, 还原法(木炭还原法, production of tungsten powder and molybdenum powder, 铁粉、钴粉), electrolysis method (aqueous solution electrolysis method, 熔盐电解法, 液态金属阴极法), spray method (with gas or water spray liquid metal), 羰基法.

二、不锈钢比例及展望

据2010年世界不锈钢消费量统计单位为3200万吨, 而世界粗钢产量设定为1.4 billion tons, stainless steel accounted for 2.3%.In 2010, China produced 620 million tons of steel and 11.26 million tons of stainless steel, accounting for 1.8%的钢铁总产量和0.比世界平均水平低5%.It is still a long way from the advanced nations of Japan, 这是10%, 和美国, 这是8%.

在前段中, 一般钢在钢铁工业中的比例达到90%左右.General steel is explained as the general purpose of steel, from the metal element called iron - carbon alloy.它是一种由多少百分比的碳元素所组成的金属铁元素. According to the carbon content, it is divided into:

铸铁(含碳量≥2%);

高碳钢(含碳量2.0%-0.65%);

中碳钢(含碳量0.65%-0.2%);

低碳钢(含碳量≤0.2%).

其余10%左右的钢是由三种金属元素组成的钢,用于特殊钢材产品.Stainless steel is a kind of special steel products, 20 years ago the proportion of stainless steel 0.5% or so developed to the current proportion of 2.3%,可以说,它也发展了很多.With the depletion of the earth's environment and resources, stainless steel has to meet the requirements of modern materials, will gradually replace the general steel part of the product.If the life of the bridge is increased to more than 120 years, 沿海码头的钢结构和混凝土钢结构需要提高使用寿命和可回收利用, 不锈钢的应用前景随着人类生活条件的变化而变化.

什么是不锈钢

1 .不锈钢的定义

Non-rust is put forward for steel is easy to rust.It is on the basis of general steel application, 钢的腐蚀是一种普遍现象, 导致钢设施不断失重和机械性能下降而报废.Prevent steel corrosion put forward the concept of rust method, 从铁的应用开始, corrosion prevention technology with the same generation, 不断创新, preservation of thousands of years of rust physical appearance to today, 但是防锈技术已经丢失了, 悲叹但仍要继续.一般钢材生锈的现象分析;浦钢的化学成分是铁(Fe)和碳(C)最简单、最经济的组合, 因为铁碳金属中的铁与空气中的活性氧接触, 反应生成此层的氧化物(FeO), 氧化亚铁称为不稳定性, iron oxide generated (Fe3O4) continue to oxidation, 氧化生产稳定性(Fe2O3)再次.在普钢表面是由以上三种结构的氧化物组成的, 在钢中腐蚀损失达到10%, and iron oxide material is scattered not recycling conditions, caused great economic loss and resources wasting, does not benefit the continuous development of economy, the research methods of stainless emerge in endlessly, 是否油漆过防锈漆, 镀合金, 涂塑, 那么材料本身就是不锈钢材料.

只有不生锈的材料才是保护环境、节约资源的有效途径.但生锈是相对的,是相对于一般碳钢来说,是有条件的.不同的环境, 不同的媒介, 不同的时间, stainless steel with ordinary carbon steel will rust.So stainless steel is not rust, but relatively rust.It is an element of chromium added in the iron-carbon alloy, which is a combination of iron-carbon-chromium three elements. 当碳含量稳定在0.2%时,铬的含量增加到12.5%(原子量百分比.5、重量百分比.6), showing rust resistance (not to be corroded in dry air).当钢中的铬低于12.5%, it is generally called alloy steel, which is relatively easy to rust.Increase the content of chromium and enhance the antirust ability.当稳定的铬含量为12.5%, the antirust ability decreases with the increase of carbon content, and the antirust ability increases with the decrease of carbon content.不锈钢必须含铬,且铬含量不小于12.5% when the steel can be called stainless steel.这是基于铬,使铬铁合金电极电位增加, 铬含量为1/8, 2/8, 3/8——原子比, iron-chromium alloy electrode potential is a jump increase, 叫做N /8定律, 这是, 合金电极电位由负电位变为正电位.不锈钢只能在正常条件下对空气中的氧气过敏,钝化后具有抗锈性, 但是一般的酸, 碱, salt medium corrosion resistance ability is very different.因为这个, 不锈钢在不锈钢的基础上适用于各种介质和环境, 利用自然界中的金属元素(74)和非金属元素(17),根据不同的用途使用二元, 三元多组分体系研究, 不锈钢似乎能满足许多钢等级的不同要求, 如酸性不锈钢0 cr18ni9 (304), 和其他材料.其他不含铬或低于12的金属.5% chromium can only be called alloy steel and alloy materials.

2 .不锈钢的腐蚀

不锈钢也有腐蚀性, 如在高温下, the surface is oxidized to form an oxide scale, 这是不争的事实.金属腐蚀发生在两个方面,一是化学腐蚀,二是电腐蚀.The corrosion of metal at high temperature is called chemical corrosion, 而金属在室温下的腐蚀称为电腐蚀.化学腐蚀称为均匀腐蚀,电腐蚀称为局部腐蚀.

1)化学腐蚀

It is common knowledge that metals corrode at high temperature.But the corrosion degree of stainless steel and steel is not the same.Stainless steel can withstand higher temperature, 如1Cr13(410)的氧化温度在500℃-600℃;1Cr17(430)的氧化温度在600℃- 700℃之间.The oxidation temperature of 0Cr18Ni8(304) is between 800℃ and 900℃.The oxidation temperature of general steel is only 200℃-300℃.不锈钢的腐蚀程度随温度的升高而增加,一般钢的腐蚀程度随时间的延长而加重.On the surface of stainless steel oxide scale to prevent reoxidation, 钢的氧化皮增加了氧化.Of course, people say, what about at room temperature?一般钢材在没有防护腐蚀措施的情况下在氧气的保护下在空气中被腐蚀掉.The normal temperature corrosion of stainless steel is much more complex, 不仅与氧有关, 但也与组织有关, 内部夹杂物, 内应力及热处理状态, 也与环境媒介有关.The next thing to talk about is 电化学 corrosion, right?(未完待续)