Piercing plug
View Patent ↗A piercing plug of the present invention includes: a plug body; a Ni—Cr layer formed on a surface of the plug body; and a sprayed coating formed on a surface of the Ni—Cr layer. The plug body contains, by mass %, 20 to 30% of Cr, 30 to 55% of Ni, 0.005 to 0.5% of C, 0.1 to 1.0% of Si, 0.2 to 1.5% of Mn, and at least one of Mo and W which satisfy a following conditional expression (A), and remainder including Fe and impurities. 1.5%≤Mo+0.5W≤8.5% (A)
1. A piercing plug comprising:
a plug body;
a Ni—Cr layer formed on a surface of the plug body, the Ni—Cr layer coming into contact with the plug body; and
a sprayed coating formed on a surface of the Ni—Cr layer,
wherein the plug body contains, by mass %, 20 to 30% of Cr, 30 to 50% of Ni, 0.005 to 0.5% of C, 0.1 to 1.0% of Si, 0.2 to 1.5% of Mn, and at least one of Mo and W which satisfy conditional expression (A): 1.5%≤Mo+0.5W≤8.5%, with a remainder including Fe and impurities.
2. The piercing plug according to claim 1 ,
wherein a heat treatment is performed at 850 to 1150° C. after the Ni—Cr layer and the sprayed coating are formed on the plug body.
3. The piercing plug according to claim 1 or 2 ,
wherein the sprayed coating contains iron and iron oxide.
4. The piercing plug according to claim 1 or claim 2 ,
wherein the sprayed coating is formed by arc-spraying a steel wire rod.
5. The piercing plug according to claim 1 or claim 2 ,
wherein a thickness of the Ni—Cr layer is 50 to 100 μm.
6. The piercing plug according to claim 3 ,
wherein the sprayed coating is formed by arc-spraying a steel wire rod.
7. The piercing plug according to claim 3 ,
wherein a thickness of the Ni—Cr layer is 50 to 100 μm.
8. The piercing plug according to claim 4 ,
wherein a thickness of the Ni—Cr layer is 50 to 100 μm.
9. The piercing plug according to claim 6 ,
wherein a thickness of the Ni—Cr layer is 50 to 100 μm.