| 摘要 |
PROBLEM TO BE SOLVED: To provide a housing for a lead coating machine wherein welding workability and cost can be decreased and life of the housing can be prolonged by making weldability of a place where crack of the housing is generated well. SOLUTION: A housing main body 1 is constituted of an alloy steel for a plastic mold and content of this alloy steel for the plastic mold is set in such a way that C is 0.10-0.20 pt.wt., Si is 0.22-0.32 pt.wt., Mn is 1.3-2.3 pts.wt., Cr is 1.35-1.55 pts.wt. and Mo is 0.1-0.5 pt.wt. The alloy steel for the plastic mold contg. such ingredients as these has such material characteristics that cracking during welding is few and cracking sensitivity after welding is little and mechanical strengths such as toughness and strength are approximately the same as those for the conventional alloy steel for the mold and as the expansion coefficient is approximately the same as that for the substance of a liner fitted in the housing main body, there exist few problems on dislocation and peeling of the liner. |
