1： What is cast iron ？ Answer ： Carbon content greater than 2.11％ It's called cast iron 。2： What kinds of cast iron can be divided into ？ Answer ： White cast iron 、 Gray cast iron 、 Ductile iron 、 Alloy cast iron 、 Malleable iron 3： What are the simple identification methods of iron and steel ？ Answer ： Spark identification 、 ...

1： What are the physical properties of metals ？ Answer ： Including density 、 Melting point 、 Thermal expansion 、 Conductivity and thermal conductivity 。2： What is called Melting point ？ Answer ： Is the temperature at which a metal changes from a solid to a liquid 。3： What is the chemical properties of metals ？ Answer ： Metal material in the room ...

1： What is pattern ? Answer ： Drawing that can accurately express the shape, size and technical requirements of an object 。2： What is projection ？ Answer ： Is a group of rays through the object to a predetermined plane to get the graphic method 。3： Classification of projection method ？ Answer ： Can be divided into centers ...