ZSE controller reported an IFR departure at less than expected standard climb rate entering a higher...

Narrative:

Aircraft X was cleared by approach to ZZZ and placed on a heading of 180 climbing to 040. The aircraft checked on with me still climbing below the mia (minimum IFR altitude) of 030 heading towards a 050 mia within a minute and a half. The aircraft was also climbing at less than a 300 ft per minute climb rate. I initially went to turn him away from the mia but he was still below the mia of 030. The pilot read it back as a question so I responded negative; maintain current heading of 180. And he read that back correct. The pilot was having a hard time hearing me also when I asked to be out of 030ft in 1 minute or less. So I asked him if he had all surrounding terrain in sight and to maintain his own terrain and obstruction clearance then I also climbed him to 050ft. Pilots should advise if they're climb rate is going to be less than 300 ft per minute especially on an IFR clearance. Better coordination should have been done with myself and pdx approach.

Original NASA ASRS Text

Title: ZSE Controller reported an IFR departure at less than expected standard climb rate entering a higher MVA.

Narrative: Aircraft X was cleared by Approach to ZZZ and placed on a heading of 180 climbing to 040. The aircraft checked on with me still climbing below the MIA (Minimum IFR Altitude) of 030 heading towards a 050 MIA within a minute and a half. The aircraft was also climbing at less than a 300 ft per minute climb rate. I initially went to turn him away from the MIA but he was still below the MIA of 030. The pilot read it back as a question so I responded negative; maintain current heading of 180. And he read that back correct. The pilot was having a hard time hearing me also when I asked to be out of 030ft in 1 minute or less. So I asked him if he had all surrounding terrain in sight and to maintain his own terrain and obstruction clearance then I also climbed him to 050ft. Pilots should advise if they're climb rate is going to be less than 300 ft per minute especially on an IFR clearance. Better coordination should have been done with myself and PDX approach.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1677227
Time
Date	201908
Local Time Of Day	0001-0600
Place
Locale Reference	ZSE.ARTCC
State Reference	WA
Aircraft 1
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Developmental
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

ZSE controller reported an IFR departure at less than expected standard climb rate entering a higher MVA.