哪几层面能影响钢结构工程的性能指标
Which layers can affect the performance index of steel structural engineering
大家都知道，钢结构关键用的原材料是钢材，而钢材产品质量的优劣直接影响了钢结构的性能指标。
As we all know, the key raw material used in steel structures is steel, and the quality of steel products directly affects the performance indicators of steel structures.
钢材是由平炉和氧气转炉熔炼而成，这两种熔炼方式提练出来的钢材产品质量相当。针对钢的脱氧工程项目也是钢材生产制造中的一个关键步骤，钢液中残余氧，将使钢材晶粒粗细不均并产生热脆。因此浇注钢锭时在炉中或盛钢桶中添加脱氧剂以消除氧，可大大的改进钢材的产品质量。
Steel is produced by melting in an open hearth furnace and an oxygen converter, and the quality of the steel products produced by these two melting methods is equivalent. The deoxidation engineering project for steel is also a key step in steel production and manufacturing. Residual oxygen in the steel liquid will cause uneven grain size and thermal embrittlement of the steel. Therefore, adding deoxidizers to the furnace or ladle during the pouring of steel ingots to eliminate oxygen can greatly improve the product quality of the steel.
碳素钢关键是铁和碳的合金。钢因含碳量不一样而区别为低碳钢、中碳钢和高碳钢。碳的含量愈高，钢的抗压强度也愈高，但其塑性、韧性和可焊性却显著减低，因此用作修建钢结构原材料的只可以是低碳钢。
The key to carbon steel is an alloy of iron and carbon. Steel is distinguished into low-carbon steel, medium carbon steel, and high carbon steel due to its different carbon content. The higher the carbon content, the higher the compressive strength of steel, but its plasticity, toughness, and weldability are significantly reduced. Therefore, only low-carbon steel can be used as a raw material for building steel structures.
钢材的性能指标受温度的影响也非常显著，在150℃以内，钢材的抗压强度、弹性模量和塑性均与常温相仿，转变并不大。但在250℃左右，抗压强度有局部性提高，延伸率和断面收缩率均降到底点，出现了所谓的“蓝脆”现象(钢材表层空气氧化膜呈蓝色)。在300℃之后，抗压强度和弹性模量均刚开始显著降低，塑性显著升高，符合600℃时，抗压强度几乎为零，塑性大幅度升高，钢材处在热塑性情况。
The performance indicators of steel are also significantly affected by temperature. Within 150 ℃, the compressive strength, elastic modulus, and plasticity of steel are similar to room temperature, and the transformation is not significant. But at around 250 ℃, there is a localized increase in compressive strength, with elongation and cross-sectional shrinkage both dropping to the bottom, resulting in the so-called "blue brittleness" phenomenon (the air oxide film on the surface of the steel is blue). After 300 ℃, the compressive strength and elastic modulus both begin to significantly decrease, and the plasticity increases significantly. At 600 ℃, the compressive strength is almost zero, and the plasticity increases significantly. The steel is in a thermoplastic state.