Fe-Ni alloy sheet for shadow mask, excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases

An Fe-Ni alloy sheet for a shadow mask excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases, which consists essentially of:

• ______________________________________ nickel (Ni) from 34 to 38 wt. %, silicon (Si) from 0.01 to 0.09 wt. %, aluminum (Al) from 0.002 to 0.020 wt. %, calcium (Ca) from 0.0002 to 0.0020 wt. %, magnesium (Mg) from 0.0003 to 0.0020 wt. %, where, Ca + 1/2 Mg from 0.0005 to 0.0025 wt. %, ______________________________________
• and
• the balance being iron and incidental impurities,
• where, the contents of carbon (C), nitrogen (N), sulfur (S), oxygen (O), phosphorus (P) and non-metallic inclusions as said incidental impurities being respectively:
• up to 0.0050 wt.% for carbon,
• up to 0.0020 wt.% for nitrogen,
• up to 0.0020 wt.% for sulfur,
• up to 0.0040 wt.% for oxygen,
• up to 0.0040 wt.% for phosphorus,
• and
• up to 0.0040 wt.% as converted into oxygen for non-metallic inclusions,
• where, 1/10 C+1/10 N+S+1/5 O+1/2 P:
• up to 0.0045 wt.%, and Ca+1/2 Mg.gtoreq.S+1/5 O;
• said non-metallic inclusions as said incidental impurities comprising a composition having a particle size of up to 6 .mu.m in a region of a melting point of at least 1,600.degree. C., which region is defined by a liquidus curve of 1,600.degree. C. in the CaO-Al.sub.2 O.sub.3 -MgO ternary phase diagram;
• and
• a surface portion of said Fe-Ni alloy sheet having a silicon (Si) segregation rate, as expressed by the following formula, of up to 10%:
• ##EQU10##

A method for manufacturing an Fe-Ni alloy sheet for a shadow mask excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases, which comprises the steps of:

• preparing an ingot or a continuously cast slab of an Fe-Ni alloy consisting essentially of:
• ______________________________________ nickel (Ni) from 34 to 38 wt. %, silicon (Si) from 0.01 to 0.09 wt. %, aluminum (Al) from 0.002 to 0.020 wt. %, calcium (Ca) from 0.0002 to 0.0020 wt. %, magnesium (Mg) from 0.0003 to 0.0020 wt. %, where, Ca + 1/2 Mg from 0.0005 to 0.0025 wt. %, ______________________________________
• and
• the balance being iron and incidental impurities,
• where, the contents of carbon (C), nitrogen (N), sulfur (S), oxygen (O) and phosphorus (P) as said incidental impurities being respectively:
• up to 0.0050 wt.% for carbon,
• up to 0.0020 wt.% for nitrogen,
• up to 0.0020 wt.% for sulfur,
• up to 0.0040 wt.% for oxygen, and
• up to 0.0040 wt.% for phosphorus,
• where, 1/10 C+1/10 N+S+1/5 O+1/2 P:
• up to 0.0045 wt.%, and Ca+1/2 Mg.gtoreq.S+1/5 O;
• subjecting said ingot or said continuously cast slab to a slabbing rolling, a scarfing, a hot rolling, a descaling, another scarfing, at least one cold rolling accompanied by a recrystallization annealing, a temper rolling and a stress-relieving annealing in this order to prepare a sheet of said Fe-Ni alloy;
• heating said ingot or said continuously cast slab, when subjecting same to said slabbing rolling, in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T)(.degree. C.) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the following formula:
• 7. 71-5.33.times.10.sup.-3 T.ltoreq.log t.ltoreq.8.00-5.33.times.10.sup.-3 T,
• then, subjecting same to said slabbing rolling at a sectional reduction rate of at least 35%, and then slowly cooling same, thereby adjusting a silicon (Si) segregation rate, as expressed by the following formula, of a surface portion of said Fe-Ni alloy sheet to up to 10%:
• ##EQU11##

A method for manufacturing an Fe-Ni alloy sheet for a shadow mask excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases, which comprises the steps of:

• preparing an ingot or a continuously cast slab of an Fe-Ni alloy consisting essentially of:
• ______________________________________ nickel (Ni) from 34 to 38 wt. %, silicon (Si) from 0.01 to 0.09 wt. %, aluminum (Al) from 0.002 to 0.020 wt. %, calcium (Ca) from 0.0002 to 0.0020 wt. %, magnesium (Mg) from 0.0003 to 0.0020 wt. %, where, Ca + 1/2 Mg from 0.0005 to 0.0025 wt. %, ______________________________________
• and
• the balance being iron and incidental impurities,
• where, the contents of carbon (C), nitrogen (N), sulfur (S), oxygen (O) and phosphorus (P) as said incidental impurities being respectively:
• up to 0.0050 wt.% for carbon,
• up to 0.0020 wt.% for nitrogen,
• up to 0.0020 wt.% for sulfur,
• up to 0.0040 wt.% for oxygen, and
• up to 0.0040 wt.% for phosphorus,
• where, 1/10 C+1/10 N+S+1/5 O+1/2 P:
• up to 0.0045 wt.%, and Ca+1/2 Mg.gtoreq.S+1/5 O;
• subjecting said ingot or said continuously cast slab to a slabbing rolling, a scarfing, a hot rolling, a descaling, another scarfing, at least one cold rolling accompanied by a recrystallization annealing, a temper rolling and a stress-relieving annealing in this order to prepare a sheet of said Fe-Ni alloy;
• heating said ingot or said continuously cast slab, when subjecting same to said slabbing rolling, in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T) (.degree. C.) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the following formula:
• 7.40-5.33.times.10.sup.-3 T.ltoreq.log t.ltoreq.7.71-5.33.times.10.sup.-3 T,
• then, subjecting same to a primary slabbing rolling as part of said slabbing rolling at a sectional reduction rate within a range of from 20 to 70%, then heating same again in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T)(.degree. C.) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the above-mentioned formula, then subjecting same to a secondary slabbing rolling as part of said slabbing rolling at a sectional reduction rate within a range of from 20 to 70%, and then slowly cooling same, thereby adjusting a silicon (Si) segregation rate, as expressed by the following formula, of a surface portion of said Fe-Ni alloy sheet to up to 10%:
• ##EQU12##

A method for manufacturing an Fe-Ni alloy sheet for a shadow mask excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases, which comprises the steps of:

• preparing an ingot or a continuously cast slab of an Fe-Ni alloy consisting essentially of:
• ______________________________________ nickel (Ni) from 34 to 38 wt. %, silicon (Si) from 0.01 to 0.09 wt. %, aluminum (Al) from 0.002 to 0.020 wt. %, calcium (Ca) from 0.0002 to 0.0020 wt. %, magnesium (Mg) from 0.0003 to 0.0020 wt. %, where, Ca + 1/2 Mg from 0.0005 to 0.0025 wt. %, ______________________________________
• and
• the balance being iron and incidental impurities,
• where, the contents of carbon (C), nitrogen (N), sulfur (S), oxygen (O), phosphorus (P) and non-metallic inclusions as said incidental impurities being respectively:
• up to 0.0050 wt.% for carbon,
• up to 0.0020 wt.% for nitrogen,
• to 0.0020 wt.% for sulfur,
• up to 0.0040 wt.% for oxygen,
• up to 0.0040 wt.% for phosphorus, and
• up to 0.0040 wt.% as converted into oxygen for non-metallic inclusions,
• where, 1/10 C+1/10 N+S+1/5 O+1/2 P:
• up to 0.0045 wt.%, and Ca+1/2 Mg.gtoreq.S+1/5 O;
• said non-metallic inclusions as said incidental impurities comprising a composition having a particle size of up to 6 .mu.m in a region of a melting point of at least 1,600.degree. C., which region is defined by a liquidus curve of 1,600.degree. C. in the CaO-Al.sub.2 O.sub.3 -MgO ternary phase diagram;
• subjecting said ingot or said continuously cast slab to a slabbing rolling, a scarfing, a hot rolling, a descaling, another scarfing, at least one cold rolling accompanied by a recrystallization annealing, a temper rolling and a stress-relieving annealing in this order to prepare a sheet of said Fe-Ni alloy;
• heating said ingot or said continuously cast slab, when subjecting same to said slabbing rolling, in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T)(.degree. C) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the following formula:
• 7. 71-5.33.times.10.sup.-3 T.ltoreq.log t.ltoreq.8.00-5.33.times.10.sup.-3 T,
• then, subjecting same to said slabbing rolling at a sectional reduction rate of at least 35%, and then slowly cooling same, thereby adjusting a silicon (Si) segregation rate, as expressed by the following formula, of a surface portion of said Fe-Ni alloy sheet to up to 10%:
• ##EQU13##

A method for manufacturing an Fe-Ni alloy sheet for a shadow mask excellent in etching pierceability, preventing sticking during annealing, and inhibiting production of gases, which comprises the steps of:

• preparing an ingot or a continuously cast slab of an Fe-Ni alloy consisting essentially of:
• ______________________________________ nickel (Ni) from 34 to 38 wt. %, silicon (Si) from 0.01 to 0.09 wt. %, aluminum (Al) from 0.002 to 0.020 wt. %, calcium (Ca) from 0.0002 to 0.0020 wt. %, magnesium (Mg) from 0.0003 to 0.0020 wt. %, where, Ca + 1/2 Mg from 0.0005 to 0.0025 wt. %, ______________________________________
• and
• the balance being iron and incidental impurities,
• where, the contents of carbon (C), nitrogen (N), sulfur (S), oxygen (O), phosphorus (P) and nonmetallic inclusions as said incidental impurities being respectively:
• up to 0.0050 wt.% for carbon,
• up to 0.0020 wt.% for nitrogen,
• up to 0.0020 wt.% for sulfur,
• up to 0.0040 wt.% for oxygen,
• up to 0.0040 wt.% for phosphorus, and
• up to 0.0040 wt.% as converted into oxygen for non-metallic inclusions,
• where, 1/10 C+1/10 N+S+1/5 O+1/2 P:
• up to 0.0045 wt.%, and Ca+1/2 Mg.gtoreq.S+1/5 O;
• said non-metallic inclusions as said incidental impurities comprising a composition having a particle size of up to 6 .mu.m in a region of a melting point of at least 1,600.degree. C., which region is defined by a liquidus curve of 1,600.degree. C. in the CaO-Al.sub.2 O.sub.3 -MgO ternary phase diagram;
• subjecting said ingot or said continuously cast slab to a slabbing rolling, a scarfing, a hot rolling, a descaling, another scarfing, at least one cold rolling accompanied by a recrystallization annealing, a temper rolling and a stress-relieving annealing in this order to prepare a sheet of said Fe-Ni alloy;
• heating said ingot or said continuously cast slab, when subjecting same to said slabbing rolling, in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T)(.degree. C.) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the following formula:
• 7.40-5.33.times.10.sup.-3 T.ltoreq.log t.ltoreq.7.71-5.33.times.10.sup.-3 T,
• then subjecting same to a primary slabbing rolling as part of said slabbing rolling at a sectional reduction rate within a range of from 20 to 70%, then heating same again in a heating atmosphere having a hydrogen sulfide (H.sub.2 S) concentration of up to 100 ppm to a temperature (T)(.degree. C.) within a range of from 1,150.degree. to 1,300.degree. C. for a period of time (t)(hr) as expressed by the above-mentioned formula, then subjecting same to a secondary slabbing rolling as part of said slabbing rolling at a sectional reduction rate within a range of from 20 to 70%, and then slowly cooling same, thereby adjusting a silicon (Si) segregation rate, as expressed by the following formula, of a surface portion of said Fe-Ni alloy sheet to up to 10%:
• ##EQU14##