1. ① high performance elastic limit σe and yield ratio σs / σb, to ensure excellent elastic properties, which can absorb a lot of flexibility without plastic deformation; ② high fatigue limit, fatigue damage is the most important form of spring First, the fatigue properties of steel composition and structure than the other, is also largely affected by the quality of steel metallurgy (such as non-metallic inclusions) and spring surface quality (such as decarburization) effects; ③ sufficient ductility and toughness in order to prevent impact fracture; ④ other properties, such as good heat treatment and plastic processing performance, to work under special conditions of heat resistance or corrosion resistance requirements.

2. Characteristics of carbon steel components with the content of alloying elements and the role of:

(1), the carbon in general, carbon spring steel wc = 0.6% ~ 0.9%, alloy spring steel wc = 0.45% ~ 0.70%, after quenching and tempering in the temperature obtained after tempering care's body tissue, can more ensure a good spring performance requirements.

(2) alloying elements for general-purpose alloy spring steel is generally low alloy steel. Plus elements of the main Si, Mn, Cr, etc., whose main role is to enhance hardenability, solid solution strengthening and improving temper resistance matrix; Adjuvant elements Mo, W, V and so strong carbon
Compounds forming elements, the main role to prevent defects in Si caused by decarburization, Mn-induced defects and improve the tempering heat stability and heat resistance.