Valve Technology Questions and Answers III

1. What is the difference between Cast iron and Cast steel?
   
   The difference between Cast iron and Cast steel is their carbon content. Cast Iron with carbon content greater than 2.06% is iron; steel with carbon content between 0.02% and 2.06% is steel.
   
2. What is carbon steel? How many categories does it fall into?
   
   An alloy of carbon and iron (when the carbon content is between 0.02% and 2.06%) is called carbon steel. According to the different carbon content, carbon steel is divided into three categories:
   
   A. Low carbon steel-C <0.25%;
   
   B. Medium carbon steel-C = 0.25%-0.60%;
   
   C. High carbon steel-C> 0.60%.
   
   In carbon steel, due to the different sulfur and phosphorus content, it can be divided into:
   
   A. Ordinary carbon steel-P≤0.045%, S≤0.050%;
   
   B. High-quality carbon steel-P≤0.040%, S≤0.040%;
   
   C. High-quality high-quality carbon steel-P≤0.035%, S≤0.030%.